JP3928203B2 - Image data recording / reproducing apparatus and method thereof - Google Patents

Description

但し、Ｘ−Ｙは、第Ｘ秒のＹ番目のフレームを示す。
【０１０４】
このように、２フレーム間隔で圧縮画像データを再生して表示しても、１フレーム間隔で圧縮画像データを再生し、表示する場合に比べて、画像の品質劣化はごく少ない。このように、画像ファイルシステム１において、ハードディスク装置３０₁ 〜３０₅ それぞれに圧縮画像データのフレームを２枚以上ずつ記録するように記録方法を変更し、記録方法に応じて再生方法を変更することにより、さらに高速な再生を行う際のシークの発生回数を減らし、高速再生を無理なく確実に行うことができる。
【０１０５】
また、ハードディスク装置の数をさらに増やし、見かけ上の記録・再生のデータレートを大きくすることにより、圧縮画像データだけではなく非圧縮画像データもリアルタイムに記録・再生するように、画像ファイルシステム１を構成することができる。
さらに、ハードディスク装置３０₁ 〜３０₅ を、例えば、ＭＯ装置あるいはＤＶＤ装置等の他のランダムアクセス可能な記録装置に置換する等、画像ファイルシステム１は、種々の構成を採ることができる。
【０１０６】
第２実施例
以下、本発明の第２の実施例を説明する。
【０１０７】
第２実施例の背景
まず、図１１を参照して、本発明の第２の実施例の背景を説明する。
図１１（ａ），（ｂ）は、ハードディスク装置３０₁ 〜３０₅ （ＤＩＳＣ）上の圧縮画像データの記録領域を例示する図である。なお、図１１（ａ），（ｂ）において、記録媒体上の太線は、圧縮画像データの記録領域を示し、▲１▼〜▲４▼は読み出しの順序を示し、ａ〜ｄは出力の順番（元の順番）を示す。
アーム３８
図１１（ａ），（ｂ）において、アーム３８は、ハードディスク装置３０₁ 〜３０₅ において、記録媒体から圧縮画像データを読み出すために用いられる。
【０１０８】
第１の実施例に示した画像ファイルシステム１（図１〜図３）は、圧縮画像データがフレーム単位にインターリーブして複数の記録装置の記録媒体に記録するので、バイト単位でインターリーブする場合に比べて、通常再生あるいは倍速再生時に生じるシークの回数を大幅に減らすことができ、圧縮画像データを安定して再生することができる。
【０１０９】
しかしながら、図１１（ａ）に示すように、部分ａ〜ｄをこの順序で含み、この順序で再生されるべき圧縮画像データが、ハードディスクの互いに離れた記録領域に記録されている場合に、アーム３８が、再生の順番ａ〜ｄの通りに▲１▼〜▲４▼の順番で各記録領域にアクセスして圧縮画像データの読み出しを行うと、アーム３８が記録媒体の最外周と最内周とを行き来するので、アーム３８の移動距離および移動時間（シーク距離，シーク時間）が長くなり、一定の時間内に必要量の圧縮画像データを読み出せなくなる可能性がある。
【０１１０】
本発明の第２の実施例は、かかる問題点に鑑みてなされたものであり、画像ファイルシステム１（図１）の制御用コンピュータ２５０（図３）等の動作を改良し、最もシーク距離およびシーク時間が短くなる順番（▲１▼〜▲４▼）で各記録領域にアクセスして圧縮画像データを読み出すようにして、一定の時間内に必要な量の圧縮画像データの読み出し、および、リアルタイムな再生画像データの供給を確実に行うことができるようにすることを目的とする。
【０１１１】
第２の実施例における制御用コンピュータ２５０等の処理
以下、第２の実施例における画像ファイルシステム１の制御用コンピュータ２５０の動作を説明する。なお、以下に示さない画像ファイルシステム１の他の構成部分の動作は、第１の実施例においてと同じである。
第２の実施例においては、制御用コンピュータ２５０は、圧縮画像データの再生時に、ファイルシステム２００が管理する記録領域に基づいて、上述のようにシーク距離が最短になる順番で記録領域にアクセスする。
なお、この部分は、説明の簡略化のために、ハードディスクおよびハードディスク装置３０₁ 〜３０₅ ではなく、ＤＶＤおよびＤＶＤ装置を例に説明する。
ＤＶＤ（図１１）には、円周方向に沿って螺旋状に記録トラックが設けられ、記録トラックはセクタに分割されている。これらのセクタそれぞれには、外周側から連続的にセクタ番号（セクタアドレス）が付与される。
【０１１２】
具体的には、例えば、記録トラックの最も外側の端のセクタにはセクタ番号０００１ｈが付与され、記録トラックの最も内側の端のセクタにはセクタ番号７ＦＦＦｈが付与され、これら両端の間のセクタには、内側に行くにつれて１ずつ増加する連続的なセクタ番号が付与される。
【０１１３】
例えば、ファイルシステム２００が管理している記録領域ａ〜ｄ〔図１１（ａ），（ｂ）〕の先頭のセクタのセクタ番号がそれぞれ、例えば、０１００ｈ，７０００ｈ，０２００ｈ，６０００ｈである場合に、入出力回路２０_i の制御用コンピュータ２５０は、圧縮画像データの再生時に、ファイルシステム２００から、これらの記録領域ａ〜ｄの先頭のセクタのセクタ番号およびデータ長を得ると、例えば、セクタ番号が単調に増加するように記録領域ａ〜ｄをソートし、図１１（ｂ）に示すように、再生の順序ａ〜ｄに係わらず、記録領域ａ，ｃ，ｄ，ｂの順番で再生するように、読み出しコマンド〔図４（Ｂ）〕のコマンド数（ Num of command;この場合は４）、アドレス（Adress；０１００ｈ，０２００ｈ，６０００ｈ，７０００ｈ）およびデータ長(Length)を設定し、ＳＤＲＡＭ制御回路２４８等を介して、タイムスロットｉでＤＶＤ装置（ハードディスク装置３０₁ 〜３０₅ ）に対して出力する。
【０１１４】
なお、ハードディスク装置３０₁ 〜３０₅ において用いられるハードディスクは、記録トラックが同心円状に設けられるが、同様に、制御用コンピュータ２５０は、ＤＶＤの場合と同様に、ハードディスクについても、セクタアドレスをソートすることにより、ＤＶＤの場合と同様に読み出しコマンドを発生することができる。
【０１１５】
図１２（Ａ）は、ハードディスク装置３０₁ 〜３０₅ から読み出される圧縮画像データの部分ａ〜ｄ〔図１１（ａ），（ｂ）〕の順番を示し、（Ｂ）は、ＲＡＭブロック２８０₁ 〜２８０₅ から出力される圧縮画像データの部分ａ〜ｄ〔図１１（ａ），（ｂ）〕の順番を示す。
【０１１６】
ハードディスク装置３０₁ 〜３０₅ は、入出力回路２０_i の制御用コンピュータ２５０から入力された読み出しコマンドに従って、圧縮画像データの部分ａ〜ｄ〔図１１（ａ），（ｂ）〕を、図１２（Ａ）に示すように、先頭セクタのセクタ番号に基づいてソートした順番〔図１１（ｂ）に示す順番▲１▼〜▲４▼，ａ，ｃ，ｄ，ｂ〕で読み出し、タイムスロットｉで入出力回路２０_i のＲＡＭブロック２８０₁ 〜２８０₅ に対して出力する。
制御用コンピュータ２５０は、ＳＤＲＡＭ制御回路２４８を介してＲＡＭブロック２８０₁ 〜２８０₅ を制御し、図１２（Ｂ）に示すように、ＲＡＭブロック２８０₁ 〜２８０₅ に入力された圧縮画像データの部分ａ，ｃ，ｄ，ｂを、再生の順序（元の順序）ａ〜ｄに並び替えて圧縮画像データをスイッチ回路２６０に対して出力させる。
【０１１７】
スイッチ回路２６０、伸長回路２６２およびエンコーダ回路２６４は、第１の実施例においてと同様に、入力された圧縮画像データをデインターリーブし、伸長復号し、さらに、エンコードしてＤ１方式あるいはＳＤＩ方式のデータストリームとして出力する。
【０１１８】
画像ファイルシステム１の動作
以下、さらに図１３を参照して、第２の実施例における画像ファイルシステム１の動作を説明する。
図１３は、第２の実施例における画像ファイルシステム１の再生処理（Ｓ１４）を示すフローチャート図である。
【０１１９】
図１３に示すように、ステップ１４０（Ｓ１４０）において、制御用コンピュータ２５０は、システム制御装置１００から制御ライン１１０を介して圧縮画像データのファイル名を指定した命令（コマンド）を得る。
【０１２０】
ステップ１４２（Ｓ１４２）において、制御用コンピュータ２５０は、システム制御装置１００から入力されたコマンドを解釈し、再生命令である場合にはＳ１４４の処理に進み、記録命令である場合にはＳ１６０の処理に進む。
【０１２１】
ステップ１４４（Ｓ１４４）において、制御用コンピュータ２５０は、ファイルシステム２００から、指定された圧縮画像データのハードディスク装置３０₁ 〜３０₅ における物理アドレス、つまり先頭セクタ番号およびデータ長を読み込む。
【０１２２】
ステップ１４６（Ｓ１４６）において、制御用コンピュータ２５０は、上述したように、圧縮画像データの各部分を記録する記録領域の先頭セクタのセクタ番号に基づいて、記録領域をソートし、アーム３８（図１１）のシーク距離が最短になるように並び変え、その情報を格納する。
【０１２３】
ステップ１４８（Ｓ１４８）において、制御用コンピュータ２５０は、ＳＤＲＡＭ制御回路２４８等を介して、ソートした順番で圧縮画像データの各部分を再生するように読み出しコマンド〔図４（Ｂ）〕を発生し、ハードディスク装置３０₁ 〜３０₅ に対して出力する。
【０１２４】
ステップ１５０（Ｓ１５０）において、ハードディスク装置３０₁ 〜３０₅ は、読出コマンドに応じて、例えば、図１１（ｂ）および図１２（Ａ）に示した順序で圧縮画像データの各部分を再生し、再生した圧縮画像データの各部分をＲＡＭブロック２８０₁ 〜２８０₅ に対して出力し、書き込む。
【０１２５】
ステップ１５２（Ｓ１５２）において、ＲＡＭブロック２８０₁ 〜２８０₅ のフレームメモリに３０フレーム分のデータがバッファリングされると、制御用コンピュータ２５０は、ＳＤＲＡＭ制御回路２４８を介してＲＡＭブロック２８０₁ 〜２８０₅ を制御し、図１２（Ｂ）に示すように、再生の順序でスイッチ回路２６０に対して出力させる。
【０１２６】
ステップ１５４（Ｓ１５４）において、制御用コンピュータ２５０は、指定した圧縮画像データの再生が終了したか否かを判断し、再生が終了していない場合にはＳ１４６の処理に戻り、終了した場合には再生処理を終了する。
【０１２７】
ステップ１６０（Ｓ１６０）において、制御用コンピュータ２５０は、デコーダ回路２２０および圧縮回路２２２を制御して、入力されるデータストリームをデコードさせて非圧縮画像データを生成し、生成した非圧縮画像データを圧縮符号化させて圧縮画像データを生成し、ＳＤＲＡＭ制御回路２４８を介してスイッチ回路２２６，２２８およびＲＡＭブロック２８０₁ 〜２８０₅ を制御して、選択したＲＡＭブロック２８０₁ 〜２８０₅ の空きバンク（フレームメモリ）に書き込む。
【０１２８】
ステップ１６２（Ｓ１６２）において、制御用コンピュータ２５０は、ＳＤＲＡＭ制御回路２４８を介してＲＡＭブロック２８０₁ 〜２８０₅ を制御し、ハードディスク装置３０₁ 〜３０₅ に対して圧縮画像データを出力させる。
【０１２９】
ステップ１６４（Ｓ１６４）において、制御用コンピュータ２５０は、圧縮画像データの記録が終了したか否かを判断し、終了しない場合にはＳ１６０の処理に戻り、終了した場合には記録処理を終了する。
【０１３０】
以上説明したように、本発明の第２の実施例によれば、第１の実施例と同様に、バイト単位でインターリーブしてハードディスク装置３０₁ 〜３０₅ に圧縮画像データを記録する場合に比べて大幅にシーク回数を減らすことができる上に、さらに、シーク距離およびシーク時間を大幅に短縮することができるので、一定時間内に必要な量の圧縮画像データをさらに確実に再生することができる。従って、本発明の第２の実施例によれば、シーク時間に起因して生じうる再生画像の劣化を、確実に防止することができる。
【０１３１】
なお、第２の実施例は、画像ファイルシステム１のようにフレーム単位でインターリーブを行う記録・再生装置の他に、従来のバイト単位でインターリーブを行う記録・再生装置にも応用することができる。
なお、本発明の第２の実施例に対しても、第１の実施例に対してと同様な変形が可能である。
【０１３２】
【発明の効果】
以上説明したように、本発明に係る画像データ記録・再生装置およびその方法によれば、不連続な記録領域に記録された複数の画像データを再生する際に、シーク距離およびシークに要する時間を極力、短くして、エラーなく画像データを再生することができ、しかも、リアルタイムな画像データを確実に再生することができる。
【図面の簡単な説明】
【図１】本発明に係る画像ファイルシステムの構成を示す図である。
【図２】図１に示した画像データ記録・再生装置の入出力制御装置の構成を示す図である。
【図３】図１に示した画像ファイルシステムの入出力回路（図２）の構成を示す図である。
【図４】（Ａ）〜（Ｃ）は、入出力回路からハードディスク装置に対して出力される命令Ｓ２４８₁ （コマンドおよびステータス）のフォーマットを示す図である。
【図５】圧縮画像データの各秒(sec) に含まれる何番目のフレーム(Frame) が、ハードディスク装置（図１，図２）のいずれに記録されるかを示す図である。
【図６】画像データ記録・再生装置（図１，図２）が画像データを再生する際の入出力回路による読み出しコマンドの発行と、ハードディスク装置による画像データの再生のタイミングを示す図である。
【図７】画像データ記録・再生装置（図１，図２）が画像データを通常再生（１倍速再生）する際に、ハードディスク装置（ＲＡＭ１〜ＲＡＭ５）が再生する圧縮画像データのフレームの順番を例示する図である。
【図８】画像データ記録・再生装置（図１，図２）が画像データを２倍速再生する際に、ハードディスク装置（ＲＡＭ１〜ＲＡＭ５）が再生する圧縮画像データのフレームの順番を例示する図である。
【図９】ハードディスク装置から圧縮画像データを読み出す制御用コンピュータの第１の処理（Ｓ１０）の内容を示す図である。
【図１０】ＲＡＭブロックから圧縮画像データを読み出して出力する制御用コンピュータの第２の処理（Ｓ１２）の内容を示す図である。
【図１１】（ａ），（ｂ）は、ハードディスク装置のハードディスク（ＤＩＳＣ）上の圧縮画像データの記録領域を例示する図である。
【図１２】（Ａ）は、ハードディスク装置（図１，図２）から読み出される圧縮画像データの部分ａ〜ｄ〔図１１（ａ），（ｂ）〕の順番を示し、（Ｂ）は、ＲＡＭブロックから出力される圧縮画像データの部分ａ〜ｄ〔図１１（ａ），（ｂ）〕の順番を示す。
【図１３】第２の実施例における画像ファイルシステムの再生処理（Ｓ１４）を示すフローチャート図である。
【符号の説明】
１…画像ファイルシステム、１００…システム制御装置、１０２₁ ，１０２₂ …ＶＴＲ装置、１０４…伝送装置、２…画像データ記録・再生装置、１８…入出力制御装置、２０₁ 〜２０₆ …入出力回路、２２…入力処理部、２２０…デコーダ回路、２２２…圧縮回路、２２４…圧縮データ制御回路、２２６〜２３０…スイッチ回路、２４…制御部、２４０…制御回路、２４２…ＲＡＭ、２４６…ＲＯＭ、２４８…ＳＤＲＡＭ制御回路、２６…出力処理部、２６０…スイッチ回路、２６２…伸長回路、２６４…エンコーダ回路、２８…出力バッファ部、２８０₁ 〜２８０₅ …ＲＡＭブロック、２００…ファイルシステム、３２…画像データバス、３４…下りバス、３４₁ 〜３４₅ …バス、３６…上りバス、３６₁ 〜３６₅ …バス、３０…記録装置、３０₁ 〜３０₅ …ハードディスク装置。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to image data for recording image data on a plurality of recording media such as magneto-optical (MO) disks and hard disks (HD) by separating (interleaving) the image data in units of frames and reproducing the recorded image data. The present invention relates to a recording / reproducing apparatus and a method thereof.
[0002]
[Background Art and Problems to be Solved by the Invention]
Video data of moving images is recorded on a randomly accessible recording medium such as an MO disk and a hard disk, and image data of an arbitrary part of arbitrary image data is reproduced in real time for broadcasting or editing. An image file device is used.
Since the data rate of image data is much larger than the recording / reproducing data rate of a normal recording / reproducing device such as a hard disk device, the conventional image file device separates the image data into a plurality of parts in units of bytes ( Interleaving) and recording in parallel to multiple hard disk devices, increasing the apparent data recording / reproducing data rate of the recording / reproducing device, and recording / reproducing real-time image data. It is configured so that playback can be performed.
[0003]
However, when there is little free space on the recording medium, the image data may be written in a discontinuous recording area (sector) of the recording medium.
Also, when editing processing is performed by specifying the part and order of image data to be reproduced without changing the recording positions of a plurality of discontinuously recorded image data using an editing device (editor) or the like. Similarly, the edited image data is recorded in discontinuous sectors of the recording medium.
[0004]
As described above, when a plurality of image data that need to be reproduced continuously in real time are interleaved in units of bytes and are separately recorded in a fine recording area, a remote recording area is accessed during reproduction. It is necessary to seek every time. Specifically, for example, when all the frames of image data interleaved in byte units are recorded in separate recording areas, a seek is required every time a different frame of image data is accessed. In this case, 30 seeks are required per second.
As described above, when frequent seeks occur, the conventional image file device cannot read out a necessary amount of image data within a predetermined time, and real-time image data cannot be reproduced or reproduced. In some cases, an error may occur in the processed image data.
[0005]
The present invention has been made in view of the above-described problems of the prior art, and when reproducing a plurality of image data recorded in a discontinuous recording area, by reducing the number of seeks as much as possible, An object of the present invention is to provide an image data recording / reproducing apparatus and method that can reproduce image data without error and can reliably reproduce real-time image data.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, an image data recording / reproducing apparatus according to the present invention comprises image data separating means for separating image data into a first predetermined number in units of frames, and a plurality of recording units, A data recording / reproducing means for recording and reproducing the image data for each frame separated by the image data separating means; and the image data separating means for multiplexing the image data reproduced by the data reproducing means in units of frames. Image data multiplexing means for returning to the order prior to separation,The data recording / reproducing means, at the time of recording the image data,The image data of the adjacent second predetermined number of frames is stored in the recording unit different for each of the second predetermined number of frames.When the recorded image data is reproduced at double speed, the image data recorded on the plurality of recording sections is output from the plurality of recording sections in the order corresponding to the double speed reproduction different from that at the time of the single speed reproduction. Plays back every 2 predetermined number of frames.
[0008]
An image data recording / reproducing apparatus according to the present invention separates (interleaves) uncompressed image data or compressed image data (image data) in units of frames, records the data in parallel on a plurality of recording media, and records the recorded image data. Play.
The image data separation means separates (interleaves) the input image data into m parts for each frame. Note that the image data separation means may separate image data frame by frame or a plurality of frames.
[0009]
The image data recording / reproducing means includes, for example, m number of recording / reproducing apparatuses such as hard disk devices, and each of the m recording / reproducing apparatuses has one image data separating means according to the control of the recording control means. Each of m portions of image data separated (interleaved) by frames or by a plurality of frames is recorded in a designated recording area.
Further, each of the m recording / reproducing devices of the image data recording / reproducing means stores a part or all of the m parts of the recorded image data in a designated recording area in accordance with the control of the reproduction control means. Play from.
[0010]
The recording control means, for example, designates the leading sector and data length (recording area) of the image data to be recorded, issues a write command, and controls m recording / reproducing devices of the image data recording / reproducing means, Each of m portions of image data separated (interleaved) by one frame or a plurality of frames is recorded in a designated recording area. In this way, by interleaving the image data frame by frame and using the m recording / reproducing devices of the image data recording / reproducing means, the number of seeks generated per second is 30 / m at most ( NTSC system).
[0011]
The playback control means, for example, designates the head sector and data length (recording area) of the image data to be played back, issues a read command, controls the m recording / playback devices of the image data recording / playback means, A part or all of the recorded image data is reproduced from the designated recording area.
Note that the reproduction control means depends on the separation method of the image data separation means (whether the frame is interleaved frame by frame or interleaved by a plurality of frames) and the reproduction mode [normal reproduction (single speed reproduction) or double speed reproduction, etc.] Thus, normal reproduction (single speed reproduction) is performed by selecting the recording / reproducing apparatus of the image data recording / reproducing apparatus for reproducing the image data and changing the designation of the head sector and the data length (recording area) of the read command. And special playback such as double speed playback.
[0012]
The image data multiplexing means buffers part or all of the image data reproduced by the image data recording / reproducing means in accordance with the control of the recording control means and the reproduction control means, and multiplexes (deinterleave) in units of frames. And return to the order before separation.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
First embodiment
The first embodiment of the present invention will be described below.
[0016]
Configuration of image file system 1
FIG. 1 is a diagram showing a configuration of an image file system 1 according to the present invention.
As shown in FIG. 1, the image file system 1 includes an image data recording / reproducing device 2, a system control device 100, a transmission device 104, and a control line 110 such as a LAN.
The image data recording / reproducing device 2 includes an input / output control device 18 and n hard disk devices (RAID 1 to n) 30.₁~ 30_nThe recording apparatus 30 has a RAID configuration including FIG. 1 shows a case where n = 5 (the same applies hereinafter).
[0017]
The image file system 1 includes the VTR device 102 by these components.₁, 102₂In addition, image data input from the communication line 120 or the like is recorded, the recorded image data is reproduced in accordance with a user operation, and the reproduced image data is reproduced as the VTR device 102.₁, 102₂And output to the communication line 120 or the like.
[0018]
Configuration of image data recording / reproducing apparatus 2
FIG. 2 is a diagram showing a configuration of the input / output control device 18 of the image data recording / reproducing device 2 shown in FIG.
As shown in FIG. 2, the input / output controller 18 of the image data recording / reproducing apparatus 2 includes m input / output circuits 20.₁~ 20_m(Hereinafter, the case where m = 6 is exemplified), the image data bus 32 and the file system 200 are configured.
[0019]
The image data bus 32 is connected to the input / output circuit 20.₁~ 20₆To hard disk drive 30₁~ 30_FiveDownstream bus 34 for transmitting image data to and hard disk device 30₁~ 30_FiveTo input / output circuit 20₁~ 20₆And an upstream bus 36 for transmitting image data.
Each of the down bus 34 and the up bus 36 is a hard disk device 30.₁~ 30_nN buses 34 respectively corresponding to₁~ 34_n, 36₁~ 36_nIncluding the case where n = 5 as described above, and the input / output circuit 20_i(1 ≦ i ≦ m; the case where m = 6 is exemplified as described above) is the hard disk device 30_j(1 ≦ j ≦ n) between the image data and the bus 34_j, 36_jIs transmitted through.
[0020]
The image data recording / reproducing apparatus 2 uses these components to convert the image data divided into frame units into the hard disk device 30.₁~ 30_FiveThe recorded image data is reproduced in accordance with a reproduction operation performed by the user of the image file system 1 via the system control device 100 (FIG. 1) or the like, and the reproduced image data is displayed on the VTR device 102.₁, 102₂And output to the transmission device 104.
[0021]
Input / output circuit 20 _i Configuration
3 shows an input / output circuit 20 of the image file system 1 shown in FIG._iIt is a figure which shows the structure of (FIG. 2).
As shown in FIG._iIs composed of an input processing unit 22, a control unit 24, an output processing unit 26, and an output buffer unit 28.
The input processing unit 22 includes a decoder circuit (D1 Decoder) 220, a compression circuit 222, a compressed data control circuit 224, and first to third switch circuits (SW1 to SW3) 226 to 230.
[0022]
The control unit 24 includes a control computer 250 and an SDRAM control circuit 248.
The control computer 250 includes a control circuit (CPU) 240, a RAM 242 and a ROM 246.
Actually, the control computer 250 (control circuit 240) and the input / output circuit 20_iControl signals are input to and output (input / output) from / to each of the components. However, in order to simplify the illustration, these control signals are omitted as appropriate in FIG.
[0023]
The output processing unit 26 includes a fourth switch circuit (SW4) 260, an expansion circuit 262, and an encoder circuit 264.
The output buffer unit 28 includes a hard disk device 30.₁~ 30_nN RAM blocks 280 corresponding to each₁~ 280_n(RAM # 1 to # 5; the case where n = 5 is illustrated as described above).
[0024]
Components of image file system 1
Hereinafter, components of the image file system 1 shown in FIGS. 1 to 3 will be described.
[0025]
System controller 100
In the image file system 1, the system control device 100 (FIG. 1) is, for example, an editing device or a broadcasting station adjustment console.₁, 102₂The control data is transmitted and received between the image data recording / reproducing apparatus 2 and the transmission apparatus 104 via the control line 110 such as a LAN, and these operations are controlled.
[0026]
VTR device 102 ₁ , 102 ₂
VTR device 102₁, 102₂Is, for example, a D1 digital VTR device that reproduces non-compressed image data (which may include audio data) recorded on a VTR tape (not shown) and outputs an image as a D1 data stream. Input / output circuit 20 of data recording / reproducing apparatus 2_i(FIG. 2).
Also, the VTR device 102₁, 102₂Is an input / output circuit 20 of the image data recording / reproducing apparatus 2._iTo non-compressed image data input as a D1 data stream is recorded on a VTR tape.
[0027]
Transmission device 104
The transmission apparatus 104 is, for example, an input / output circuit 20 of the image data recording / reproducing apparatus 2 via a transmission line of the SDI method (SMPTE259M)._iAnd the input / output circuit 20_iIs transmitted as an SDI data stream to a transmission device (not shown) of another broadcasting station via a digital high-speed communication line or a communication line 120 of an ATM communication line.
The transmission device 104 also receives uncompressed image data input as an SDI data stream from a transmission device or the like of another broadcasting station via the communication line 120, and inputs / outputs the image data recording / reproducing device 2. 20_iOutput for.
[0028]
File system 200
The file system 200 is controlled by the input / output circuit 20 in accordance with the control of the system control apparatus 100 via the control line 110.₁~ 20₆Is the hard disk drive 30₁~ 30_FiveFor example, the recording area of the image data to be recorded is managed in units of sectors.
In addition, when reproducing the image data designated by the user, the file system 200 assigns the designated image data recording area to the input / output circuit 20.₁~ 20₆Notify
[0029]
In addition, the file system 200 is supplied from, for example, a clock generator (not shown) and based on a reference frame synchronization signal FS used for synchronizing the devices in the broadcasting station, the input / output circuit 20_iA time slot signal TS indicating a time slot to be assigned to the input / output circuit 20 together with the reference frame synchronization signal FS._iOutput for.
[0030]
Input / output circuit 20 _i
In the input / output controller 18 of the image data recording / reproducing apparatus 2, the input / output circuit 20_i(FIG. 2) shows the VTR device 102₁, 102₂The compressed image data is generated by compressing and encoding the uncompressed image data included in the D1 or SDI data stream input to the image input terminal from the transmission device 104 or the like, and the generated compressed image data is separated into frames. (Interleaved) and separated (interleaved) compressed image data (SBXOut) is sequentially received by one frame at a time in the bus 34.₁~ 34_FiveVia the hard disk drive 30₁~ 30_FiveAre recorded on a hard disk that can be accessed randomly.
[0031]
The input / output circuit 20_iThe hard disk device 30₁~ 30_FivePlays one frame at a time,₁~ 36_nCompressed image data (SBXIn) supplied via, is multiplexed (deinterleaved) and returned to the original compressed image data, and the compressed image data restored is decompressed and decoded to generate uncompressed image data, D1 System or SDI data stream from the image output terminal to the VTR device 102₁, 102₂Alternatively, the data is output to the transmission device 104 or the like.
[0032]
The input / output circuit 20_iOperates in synchronization with the time slot signal TS input from the file system 200, and each input / output circuit 20_iIs a time slot (i-th time slot) indicated by the self time slot STS to which a unique value is fixedly assigned to the hard disk device 30.₁~ 30_FiveTransmit image data to and from.
[0033]
That is, for example, the file system 200 is connected to the input / output circuit 20.₁~ 20₆When assigning time slots with a 1-second period to each, the input / output circuit 20_iThe number of time slots per cycle is 10 (the time length of one time slot is 1/10 second), and the first to sixth time slots among these 10 time slots are considered. In each, the input / output circuit 20₁~ 20₆Is the hard disk drive 30₁~ 30_FiveImage data is transmitted to and from.
[0034]
Control unit 24
The control unit 24 includes an input / output circuit 20_iThe control of each component part is performed.
[0035]
Control computer 250
In the control unit 24, the control computer 250 includes a multitasking OS and operates in synchronization with the reference frame synchronization signal FS, the time slot signal TS input from the file system 200, and the self time slot signal STS. SDRAM control circuit 248 and input / output circuit 20 in accordance with control data input from system control device 100 via control line 110._iAre controlled in parallel.
[0036]
SDRAM control circuit 248
The SDRAM control circuit 248 executes a command (command) S248 according to the control of the control computer 250.₁, Switch control signal S248₂~ 248_FourAnd buffering control signal S248_FiveIs generated and the hard disk device 30 is generated.₁~ 30_Five, Switch circuits 226 to 230, 260 and RAM block 280₁~ 280_FiveOutput for.
[0037]
Instruction S248₁The hard disk device 30₁~ 30_FiveThe operation of recording and reproducing (recording / reproducing) compressed image data is controlled.
4A to 4C show the input / output circuit 20._iTo hard disk drive 30₁~ 30_FiveInstruction S248 output for₁It is a figure which shows the format of (command and status).
[0038]
When recording image data, the SDRAM control circuit 248 executes a write command (command) shown in FIG.₁Hard disk device 30 as₁~ 30_FiveTo the hard disk device 30 managed by the file system 200₁~ 30_FiveNew compressed image data is recorded in the empty recording area.
As shown in FIG. 4A, the write command includes a sync code, a time slot identifier, a write flag, a number of commands (Num of command), an address (Adress), and a data length. (Length), and the compressed image data (Data) to be recorded is the hard disk device 30 following this command.₁~ 30_FiveIs output for.
[0039]
Of the write commands, the sync code is a unique code indicating that the data following the sync code is an instruction.
The time slot identifier (Timeslot ID) is the input / output circuit 20 that generated the instruction._iSelf time slot STS of the hard disk device 30₁~ 30_FiveCompressed image data reproduced by the input / output circuit 20_iShows the time slot used for output.
[0040]
The write flag indicates whether the instruction is a write command or a read command, and takes a value of 1 if it is a write command and 0 if it is not a write command.
The command number (Num of command) indicates the number of commands following the command number. In the case of a write command, since the first sector number (address) and data length (Length) of the recording area for recording the compressed image data is followed by one set after the command number, the value of the command number is 1
[0041]
When reproducing the image data, the SDRAM control circuit 248 sends a read command (command) shown in FIG. 4B to the command S248.₁Hard disk device 30 as₁~ 30_FiveThe hard disk device 30 that the compressed file data designated by the user is managed by the file system 200₁~ 30_FivePlayback from the recording area.
[0042]
As shown in FIG. 4B, the read command includes a sync code, a time slot identifier (Timeslot ID), a write flag (Write flag), a command number (Num of command), and commands 1, 2,. (Command1, command2, ...).
In the read command, the synchronization code (Sync code) and the time slot identifier (Timeslot ID) are the same as those in the write command described above.
The value of the write flag is 0 indicating a read command.
The number of commands (Num of command) is the same as that of the hard disk device 30.₁~ 30_FiveThis is a value corresponding to the number of commands (command1, command2,...) Composed of a combination of the first sector (address; Address) of the compressed image data to be read out and the data length (Length).
[0043]
The read status is determined by the hard disk device 30.₁~ 30_FiveHowever, the hard disk device 30₁~ 30_FiveThis state is used to notify the control computer 250 of the state.
[0044]
Further, the switch control signal S248₂, S248_ThreeSwitch circuit 226, 230 and switch circuit 228 receives command S248.₁Is selected, the input terminal b side is selected. In other cases, the input terminal a side is selected.
Further, the switch control signal S248_FourThe switch circuit 260 sequentially selects the input terminals a to e for each frame of the reference frame synchronization signal FS, and multiplexes the compressed image data input from the selected input terminals one frame at a time (deinterleave). Thus, the switch circuit 260 is controlled.
Also, the buffering control signal S248_FiveThe RAM block 280 of the output buffer unit 28₁~ 280_FiveThe buffering operation is controlled by switching the frame memory (bank).
[0045]
Input processing unit 22
The input processing unit 22 is connected to the VTR device 102.₁, 102₂Alternatively, the uncompressed image data included in the D1 or SDI data stream input from the transmission apparatus 104 is compression-encoded, and the RAM block 280 of the output buffer unit 28 is encoded.₁~ 280_FiveOutput for.
[0046]
Decoder circuit 220
In the input processing unit 22, the decoder circuit 220 (FIG. 3) is connected to the VTR device 102.₁, 102₂Decode the D1 data stream input from the terminal or the SDI data stream input from the transmission apparatus 104, and separate (interleave) uncompressed image data at a data rate of about 270 Mbps (including 180 Mbps for images) And output to the compression circuit 222.
In addition, the decoder circuit 220 includes the VTR device 102.₁, 102₂Alternatively, the frame synchronization signal is extracted from the data stream input from the transmission apparatus 104 and output to the compression circuit 222.
[0047]
Compression circuit 222
The compression circuit 222 operates in synchronization with the reference frame synchronization signal FS and the frame synchronization signal input from the decoder circuit 220, and performs discrete cosine transform (DCT) processing on the uncompressed image data input from the decoder circuit 220. Then, compression encoding is performed by performing variable length encoding or the like, and intra compressed image data having a data rate of about 30 Mbps is generated and output to the input terminal a of the switch circuit 226.
[0048]
Compressed data control circuit 224
In the compressed data control circuit 224, in synchronization with the reference frame synchronization signal FS, the switch circuit 228 sequentially selects the output terminals a to e for each reference frame synchronization signal FS and one cycle, and the compressed image is output from the selected output terminal. Data is stored in RAM block 280₁~ 280_FiveA switch control signal S224 that is controlled so as to be output is generated and output to the input terminal a of the switch circuit 230.
[0049]
Note that the compressed data control circuit 224 can be configured to change the output terminal selected by the switch circuit 228 in synchronization with the frame synchronization signal generated by the compression circuit 222, as indicated by the dotted arrow in FIG. It is.
However, since the delay of the frame synchronization signal generated by the compression circuit 222 with respect to the frame signal FS is as small as several bits of compressed image data, either the reference frame synchronization signal FS or the frame synchronization signal generated by the compression circuit 222 is used. The compressed data control circuit 224 sequentially converts the compressed image data input from the compression circuit 222 into the RAM block 280.₁~ 280_FiveThe switch control signal S224 for controlling the switch circuit 228 can be generated so that each frame is buffered one frame at a time.
[0050]
Switch circuit 226
As described above, the switch circuit 226 receives the switch control signal S248.₂Accordingly, when the switch circuit 228 outputs the compressed image data, the input terminal a side is selected and the compressed image data input from the compression circuit 222 is output to the input terminal of the switch circuit 228.
Further, the switch circuit 226 has the switch circuit 228 that receives the command S248.₁Is selected, the input terminal b side is selected and the instruction S248 is selected.₁RAM block 280₁~ 280_FiveOutput for.
[0051]
Switch circuit 230
As described above, the switch circuit 230 switches the switch control signal S248.₂Accordingly, when the switch circuit 228 outputs the compressed image data, the input terminal a side is selected and the switch control signal S224 input from the compressed data control circuit 224 is output to the switch circuit 228.
Further, the switch circuit 230 has the switch circuit 228 that receives the command S248.₁Is output, the input terminal b side is selected and the switch control signal S248 is selected._ThreeIs output to the switch circuit 228.
[0052]
Switch circuit 228
As described above, the switch circuit 228 operates in accordance with the switch control signals S224 and S248, and selects the output terminals a to e in order for each reference frame synchronization signal FS and one cycle when outputting compressed image data. Then, the compressed image data input from the compression circuit 222 via the switch circuit 226 is separated (interleaved) in units of frames, and the RAM block 280 is separated.₁~ 280_FiveAre sequentially output.
In other words, for example, the output buffer unit 288 receives the pth to (p + 4) th [p is a multiple of n (5)] frames of compressed image data input from the compression circuit 222 via the switch circuit 226, respectively. Output from output terminals a to e, separate (deinterleave), and RAM block 280₁~ 280_FiveOutput for.
[0053]
Further, the switch circuit 228 receives the command S248.₁When any of the output terminals a to e is selected, the instruction S248 input from the SDRAM control circuit 248 is selected.₁The target hard disk device 30₁~ 30_FiveOutput for.
[0054]
Output processing unit 26
The output processing unit 26 includes a hard disk device 30.₁~ 30_FivePlays back the RAM block 280₁~ 280_FiveThe VTR apparatus 102 multiplexes (deinterleaves) the compressed image data input in units of frames via the video, decompresses and decodes the data.₁, 102₂Alternatively, it is output to the transmission device 104.
[0055]
Switch circuit 260
As described above, the switch circuit 260 switches the switch control signal S248._FourIn accordance with the reference frame synchronization signal FS, the input terminals a to e are sequentially selected for each cycle, and the compressed image data input from the selected input terminal is multiplexed (deinterleaved) by one frame, Play compressed image data.
That is, for example, the switch circuit 260 includes the RAM block 280.₁~ 280_FiveAre multiplexed (deinterleaved) and output to the expansion circuit 262.
[0056]
Expansion circuit 262
The decompression circuit 262 performs a process corresponding to the compression circuit 222 on the compressed image data input from the switch circuit 260 to perform decompression decoding, generates uncompressed image data, and outputs it to the encoder circuit 264.
[0057]
Encoder circuit 264
The encoder circuit 264 encodes the uncompressed image data input from the decompression circuit 262, generates a D1 or SDI data stream, and₁, 102₂Alternatively, it is output to the transmission device 104.
[0058]
Output buffer unit 28
The output buffer unit 28 includes a hard disk device 30.₁~ 30_FiveThe buffered compressed image data is output to the switch circuit 260 of the output processing unit 26.
Further, the output buffer unit 28 buffers the compressed image data input from the switch circuit 228 of the input processing unit 22, and the hard disk device 30.₁~ 30_FiveOutput for.
[0059]
RAM block 280 _j
RAM block 280_jIs composed of, for example, three frame memories (RAM; banks 1 to 3) each having a storage capacity of 1 second of compressed image data (30 frames, in the case of the NTSC system), and operates according to the control of the SDRAM control circuit 248 To do.
The SDRAM control circuit 248 includes a RAM block 280._jAny one of the three frame memories is sent to the buffering control signal S248._FiveTo select through.
[0060]
RAM block 280_jThe selected frame memory is the switch circuit 228 of the input processing unit 22 or the hard disk device 30.₁~ 30_FiveThe compressed image data input from is buffered frame by frame.
The selected frame memory is the switch circuit 228 or the hard disk device 30.₁~ 30_FiveWhen buffering the compressed image data input from 1 second (30 frames), the SDRAM control circuit 248 controls the selected frame memory to store the buffered compressed image data corresponding to the hard disk device 30._iAlternatively, the output is made to the switch circuit 228, and the selection of the frame memory is changed.
[0061]
That is, for example, the RAM block 280₁~ 280_FiveSequentially buffer the pth to (p + 4) th frames of the compressed image data interleaved by the switch circuit 228, and when 30 frames of compressed image data are accumulated, the hard disk device 30₁~ 30_FiveOutput for each.
For example, the RAM block 280₁~ 280_FiveAre respectively hard disk devices 30.₁~ 30_FiveSequentially buffer p-th to (p + 4) -th frames of the compressed image data reproduced, and output them to the switch circuit 260 of the output processing unit 26.
[0062]
The RAM block 280_iIs composed of three frame memories because the hard disk device 30_jImage data input from the switch circuit 228, compressed image data input from the switch circuit 228, and the hard disk device 30₁~ 30_FiveRAM block 280 even when an instruction to be output conflicts with_jThis is to prevent overflow from occurring.
[0063]
Hard disk device 30 ₁ ~ 30 _Five
Hard disk device 30₁~ 30_FiveThe input / output circuit 20 of the input / output control device 18₁~ 20₆The input / output circuit 20_iWhen a recording command is input from the input / output circuit 20_iThe compressed image data input from is sequentially recorded frame by frame.
That is, for example, the hard disk device 30₁~ 30_FiveRespectively, RAM block 280₁~ 280_FiveP-th to (p + 4) -th frames of the compressed image data input from are stored.
[0064]
Further, the hard disk device 30₁~ 30_FiveThe input / output circuit 20_iWhen a reproduction command is input from the reproduction command, the recorded compressed image data is reproduced, and for example, the reproduced compressed image data is sequentially input / output circuit with a time slot including the reproduction command and a time corresponding to two time slots. 20_iOutput for.
That is, for example, the hard disk device 30₁~ 30_FiveRespectively reproduce the p-th to (p + 4) -th frames of the stored compressed image data, and the RAM block 280.₁~ 280_FiveRespectively.
[0065]
Operation of image file system 1
Hereinafter, the operation of the image file system 1 will be described with further reference to FIGS.
[0066]
Recording operation
The user operates the system control device 100 (FIG. 1) to designate the file name of the image data, and the VTR device 102₁, 102₂Alternatively, the image data recording / reproducing apparatus 2 supplied by the transmission apparatus 104 is instructed to record image data.
The system control device 100 controls each component of the image data recording / reproducing device 2 according to a user operation, and prepares to record image data.
[0067]
That is, in accordance with the control of the system control device 100, the VTR device 102₁, 102₂Alternatively, the input / output circuit 20 of the input / output control device 18 to which the data stream is supplied from the transmission device 104.₁~ 20₆Any of (input / output circuit 20_i) SDRAM control circuit 248 causes the switch circuits 226 and 230 to select the contact b side, and sequentially switches the connection of the switch circuit 228 to switch the hard disk device 30 in the i-th time slot.₁~ 30_FiveFor each, the write command shown in FIG.
Further, the SDRAM control circuit 248 causes the switch circuits 226 and 230 to select the contact a side when the transmission of the write command is completed.
[0068]
VTR device 102₁, 102₂Alternatively, the transmission device 104 is connected to the input / output circuit 20._iWhen a 270 Mbps D1 or SDI data stream is supplied to (FIGS. 2 and 3), the decoder circuit 220 decodes the supplied data stream, generates uncompressed image data of about 180 Mbps, and further includes a frame. The synchronization signal is extracted and output to the compression circuit 222.
The compression circuit 222 compresses and encodes the uncompressed image data input from the decoder circuit 220 and outputs it to the input terminal of the switch circuit 228.
[0069]
The SDRAM control circuit 248 sequentially switches the connection of the switch circuit 228, and compresses the compressed image data input from the compression circuit 222 one frame at a time in the RAM block 280.₁~ 280_FiveOutput for.
RAM block 280₁~ 280_FiveIs a buffering control signal S248._FiveWhen the compressed image data is buffered for 30 frames in accordance with the control of the SDRAM control circuit 248 via the hard disk device 30,₁~ 30_FiveThe SDRAM control circuit 248 outputs the RAM block 280.₁~ 280_FiveChange the frame memory selection.
[0070]
FIG. 5 shows the number of frames (Frame) included in each second (sec) of the compressed image data.₁~ 30_FiveIt is a figure which shows which is recorded in (FIG. 1, FIG. 2).
Hard disk device 30₁~ 30_FiveRespectively, according to the write command, the RAM block 280₁~ 280_FiveInput / output circuit 20 via_iCompressed image data input every 30 frames in the i-th time slot from the switch circuit 228 is recorded in the recording area indicated by the data length from the sector indicated by the address of the write command.
[0071]
By the operation of the image file system 1 described above, the hard disk device 30₁~ 30_FiveThe compressed image data is interleaved and recorded as shown in FIG. That is, the hard disk device 30_jThe (5 × q + j) th frame of 30 frames of compressed image data of each second is recorded (q = 0,..., 4).
[0072]
Normal playback operation
Hereinafter, an operation when the image file system 1 performs normal reproduction (1 × speed reproduction) of image data will be described.
FIG. 6 shows an input / output circuit 20 when the image data recording / reproducing apparatus 2 (FIGS. 1 and 2) reproduces image data.₁~ 20₆Issuing a read command by the hard disk device 30₁~ 30_FiveFIG. 6 is a diagram showing the timing of reproduction of image data by.
FIG. 7 shows the hard disk device 30 when the image data recording / reproducing apparatus 2 (FIGS. 1 and 2) reproduces image data normally (single speed reproduction).₁~ 30_FiveIt is a figure which illustrates the order of the frame of the compression image data which (RAM1-RAM5) reproduces.
[0073]
The user operates the system control device 100 (FIG. 1) to designate the file name of the image data, and the VTR device 102₁, 102₂Alternatively, an operation for instructing normal reproduction of image data to the image data recording / reproducing apparatus 2 supplied by the transmission apparatus 104 is performed.
The system control apparatus 100 controls each component of the image data recording / reproducing apparatus 2 according to a user operation, and prepares normal reproduction of the image data.
[0074]
In accordance with the control of the system control device 100 described above, the input / output circuit 20_iThe SDRAM control circuit 248 causes the switch circuits 226 and 230 to select the contact b side, and further switches the connection of the switch circuit 228 in order, and in the i-th time slot as shown in FIG.₁~ 30_FiveThen, the read command shown in FIG.₁~ 280_FiveTo send out.
[0075]
In the case of normal playback (single speed playback) operation, the input / output circuit 20_iIn the i-th time slot, the SDRAM control circuit 248 of the SDRAM control circuit 248 reads the read command so as to cover the entire recording area of the specified compressed image data based on the recording area managed by the file system 200 [FIG. )] Command number (Num of command), address (Adress) and data length (Length) are set and transmitted, and the hard disk device 30₁~ 30_FiveThen, all the frames of the designated compressed image data are reproduced in order.
[0076]
A specific example is given.
For example, all of the designated compressed image data is stored in the hard disk device 30.₁~ 30_Five, The SDRAM control circuit 248 sets the value of the command number (Num of command) of the read command to 1 and sets the address (Adress) value of the recording area. The hard disk device 30 has the head sector number and the data length of the compressed image data designated by the data length (Length).₁~ 30_FiveThe compressed image data is reproduced.
[0077]
The hard disk device 30 that has received the read command₁~ 30_FiveRead out the compressed image data indicated by the address (Adress) and the data length (Length) of the read command [FIG. 4B] from the hard disk, and for example, as shown in FIG. In order from the (i + 3) th time slot, the input / output circuit 20_iOutput for.
By repeating the operation described above, the input / output circuit 20_iAre the (5 × p + j) th frames of each second of the compressed image data in the order shown in FIG.₁~ 30_FiveRead from each.
[0078]
RAM block 280₁~ 280_FiveAre respectively hard disk devices 30.₁~ 30_Five1 is buffered frame by frame and output to the switch circuit 260.
The SDRAM control circuit 248 receives the switch control signal S248._FourThe switch circuit 260 is controlled via the RAM block 280, the connection of the switch circuit 260 is sequentially switched, and the RAM block 280 is switched.₁~ 280_FiveAre multiplexed (deinterleaved), returned to the original compressed image data order, and output to the decompression circuit 262.
[0079]
The decompression circuit 262 decompresses and decodes the deinterleaved compressed image data, and outputs the obtained uncompressed image data to the encoder circuit 264.
The encoder circuit 264 encodes the uncompressed image data input from the decompression circuit 262, generates a data stream of the D1 system or the SDI system, and the VTR device 102₁, 102₂And output to the transmission device 104.
[0080]
Double speed playback operation
The operation when the image file system 1 reproduces image data at double speed will be described below by taking double speed reproduction as an example.
8 shows the hard disk device 30 when the image data recording / reproducing apparatus 2 (FIGS. 1 and 2) reproduces the image data at double speed.₁~ 30_FiveIt is a figure which illustrates the order of the frame of the compression image data which (RAM1-RAM5) reproduces.
[0081]
The user operates the system control device 100 (FIG. 1) to designate the file name of the image data, and the VTR device 102₁, 102₂Alternatively, an operation for instructing the image data recording / reproducing apparatus 2 supplied by the transmission apparatus 104 to perform double speed reproduction of the image data is performed.
The system control apparatus 100 controls each component of the image data recording / reproducing apparatus 2 in response to a user operation, and prepares for double-speed reproduction of the image data.
[0082]
Similar to the normal playback, the input / output circuit 20 is controlled according to the control of the system controller 100._iThe SDRAM control circuit 248 causes the switch circuits 226 and 230 to select the contact b side, and further switches the connection of the switch circuit 228 in order, and in the i-th time slot as shown in FIG.₁~ 30_FiveThen, the read command shown in FIG.₁~ 280_FiveTo send out.
[0083]
The hard disk device 30₁~ 30_FiveSince frames of compressed image data are recorded in the order shown in FIG. 4, the SDRAM control circuit 248 includes the hard disk device 30.₁The first frame of 0 seconds is reproduced with respect to the hard disk device 30._Three, The third frame of 0 seconds is reproduced, and the hard disk device 30_FiveThe fifth frame of 0 seconds is played back to the hard disk device 30.₂7th frame of 0 seconds is reproduced with respect to the hard disk device 30_FourThe number of commands of the read command [FIG. 4B] (Num) so that different frames are reproduced in a different order from that in the normal reproduction operation, such as reproducing the ninth frame of 0 seconds. of command), address (Adress) and data length (Length) are set, and the hard disk device 30₁~ 30_FiveNeeds to be output.
[0084]
A specific example is given.
For example, all of the designated compressed image data is stored in the hard disk device 30.₁~ 30_FiveEven in the case of recording in one continuous recording area in FIG. 1, unlike the normal reproduction, the DRAM control circuit 248 sets the value of the number of read commands (Num of command) to 6 and sets 6 addresses. (Adress) and data length (Length) are set, and the hard disk device 30₁~ 30_FiveIt is necessary to reproduce the compressed image data.
[0085]
The hard disk device 30 that has received the read command₁~ 30_FiveRead out the compressed image data indicated by the address (Adress) and the data length (Length) of the read command [FIG. 4B] from the hard disk, and wait for two time slots as shown in FIG. Sequentially, the input / output circuit 20_iOutput for.
By repeating the operation described above, the input / output circuit 20_iAre the hard disk drives 30 in the order shown in FIG.₁~ 30_FiveFrom each, the frames of the compressed image data are read every other frame.
[0086]
RAM block 280₁~ 280_FiveIn the same manner as during normal playback, respectively.₁~ 30_Five1 is buffered frame by frame and output to the switch circuit 260.
The SDRAM control circuit 248 has a switch control signal S248 as in the normal reproduction._FourThe switch circuit 260 is controlled via the RAM block 280, the connection of the switch circuit 260 is sequentially switched, and the RAM block 280 is switched.₁~ 280_FiveThe frame of compressed image data input from is deinterleaved, returned to the original compressed image data order, and output to the decompression circuit 262.
[0087]
The decompression circuit 262 decompresses and decodes the deinterleaved compressed image data, and outputs the obtained uncompressed image data to the encoder circuit 264, as in normal playback.
The encoder circuit 264 encodes the uncompressed image data input from the decompression circuit 262 in the same way as during normal reproduction, generates a D1 or SDI data stream, and the VTR device 102₁, 102₂And output to the transmission device 104.
[0088]
The processing of the control computer 250 of the image file system 1 will be described below with further reference to FIGS. 9 and 10.
FIG. 9 shows the hard disk device 30.₁~ 30_FiveIt is a figure which shows the content of the 1st process (S10) of the computer 250 for control which reads compressed image data from.
FIG. 10 shows a RAM block 280.₁~ 280_FiveIt is a figure which shows the content of the 2nd process (S12) of the computer 250 for control which reads and outputs compressed image data from.
The first process and the second process shown in FIGS. 9 and 10 are started at the beginning of each period of the reference frame synchronization signal FS, and are performed in parallel by the function of the multitask OS of the control computer 250. Can be done.
[0089]
As shown in FIG.₁~ 30_FiveIn the case of performing the first process of reading the compressed image data from the control computer 250, the control computer 250 selects the bank A (first frame memory) by controlling the SDRAM control circuit 248 in step 100 (S100). Hard disk device 30₁~ 30_FiveFrom which the compressed image data is written, and the value of the reproduction permission flag is set to 0.
When the value of the reproduction permission flag is 0, the hard disk device 30₁~ 30_FiveTo RAM block 280_jUntil the reading of the compressed image data to the bank A (first frame memory) is completed, the decompression decoding process of the decompression circuit 262 is prohibited.
[0090]
In step 102 (S102), the input / output circuit 20_iThe control computer 250 compares the self time slot signal STS with the time slot signal input from the file system 200, and if they match (is its own time slot), the process proceeds to S104. If they do not match, the process remains in S102.
[0091]
In step 104 (S104), the input / output circuit 20_iThe control computer 250 controls the SDRAM control circuit 248 to set the number of commands (Num of command), address (Adress), and data length (Length) of the read command [FIG. The setting is changed as described above depending on whether the playback is 1 × or 2 ×, and the RAM block 280 is changed.₁~ 280_FiveVia the hard disk drive 30₁~ 30_FiveOutput for.
[0092]
In step 106 (S106), the input / output circuit 20_iHard disk device 30 that has received a read command from₁~ 30_FivePlays the compressed image data indicated by the read command, waits for two time slots, and inputs / outputs circuit 20_iThe compressed image data reproduced is output.
[0093]
In step 108 (S108), the input / output circuit 20_iRAM block 280 of₁~ 280_FiveThe hard disk device 30₁~ 30_FiveThe compressed image data input from is taken in and buffered.
[0094]
In step 110 (S110), the RAM block 280₁~ 280_FiveWhen the compressed image data for 30 frames is buffered, the control computer 250 sets the value of the reproduction permission flag to 1 and permits the decompression circuit 262 to perform the decompression decoding process.
[0095]
In step 112 (S112), the control computer 250 controls the SDRAM control circuit 248 to control the RAM block 280.₁~ 280_FiveSwitch the bank. That is, when the bank A (first frame memory) is in the write-permitted state until the processing of S110, the bank B (second frame memory) is set in the write-permitted state. When B and C (second and third frame memories) are in a write-permitted state, banks C and A (third and first frame memories) are set in a write-permitted state.
[0096]
As shown in FIG. 10, a RAM block 280₁~ 280_FiveIn the case where the second process of reading out and outputting the compressed image data from is performed, the control computer 250 controls the SDRAM control circuit 248 to control the RAM block 280 in step 120 (S120).₁~ 280_FiveBank A (first frame memory) is selected, and compressed image data can be read from the first frame memory.
[0097]
In step 122 (S122), the control computer 250 determines whether or not the value of the reproduction permission flag is 1. If the value of the regeneration permission flag is 1, the control computer 250 proceeds to the process of S124. If the value of the regeneration permission flag is 0, the control computer 250 remains in the process of S122. In other words, the control computer 250 determines that the RAM block 280 in the process of S122.₁~ 280_FiveWait until the compressed image data is written in the frame memory and the value of the reproduction permission flag becomes 1.
[0098]
In step 124 (S124), the control computer 250 controls the decompression circuit 262 so that the RAM block 280 depends on the playback method, that is, normal playback or double speed playback.₁~ 280_FiveThe compressed image data for 30 frames buffered in the above is decompressed and decoded and output via the encoder circuit 264.
[0099]
In step 126 (S126), the control computer 250 controls the SDRAM control circuit 248 so that the RAM block 280 is the same as the process of S112.₁~ 280_FiveSwitch the bank (frame memory) selection.
[0100]
In the first embodiment, the operation of the image file system 1 has been described by taking normal reproduction and double speed reproduction as an example. However, the number of read commands (Num of command), address (Adress), and data length (Length By appropriately changing the value of), the image file system 1 can perform a high-speed reproduction operation such as a triple-speed reproduction operation or more and a four-times reproduction or higher.
[0101]
Also, the image file system 1 performs interleaving in units of frames, and the hard disk device 30.₁~ 30_FiveSince the compressed image data is recorded on the hard disk device 30, the compressed image data is recorded on the hard disk device 30 as compared with the case where the interleaving is performed in byte units.₁~ 30_FiveRequires fewer seeks.
As a specific example, when compressed image data is interleaved in units of bytes and each frame is recorded in a separate recording area, a maximum of 30 seeks per second occurs in each time slot (NTSC system). in the case of). However, when interleaving is performed in units of frames as in the image file system 1, even when each frame is recorded in a separate recording area, the maximum number of times is 6 (= 30 / m, NTSC system). Only seek. Therefore, according to the image file system 1, it is possible to prevent a problem that the compressed image data is lost due to frequent seeks and the quality of the reproduced image is deteriorated.
[0102]
Further, for example, the recording method of the image file system 1 can be changed so as to record the compressed image data for each of a plurality of frames, and the occurrence of seek during double speed reproduction can be further reduced.
A specific example is given. For example, as shown in Table 1 below, the hard disk device 30₁The first and second frames of each second are recorded in the hard disk device 30.₂The hard disk drive 30 stores the compressed image data by two frames so that the third and fourth frames of each second are recorded in₁~ 30_FiveRecorded on the hard disk device 30 during double-speed playback.₁The first and second frames of each second are reproduced from the hard disk device 30._ThreeThe compressed image data is stored in the hard disk device 30 so that the fifth and sixth frames of each second are reproduced.₁~ 30_FiveWhen two frames are reproduced from each, data for 30 frames per second can be read out with a maximum of three seeks.
[0103]
[Table 1]

However, XY indicates the Yth frame of the Xth second.
[0104]
As described above, even when the compressed image data is reproduced and displayed at intervals of two frames, the quality of the image is hardly deteriorated as compared with the case where the compressed image data is reproduced and displayed at intervals of one frame. As described above, in the image file system 1, the hard disk device 30.₁~ 30_FiveBy changing the recording method to record two or more frames of compressed image data each, and changing the playback method according to the recording method, the number of seek occurrences when performing higher speed playback is reduced, High-speed playback can be performed without difficulty.
[0105]
Further, by further increasing the number of hard disk devices and increasing the apparent recording / reproduction data rate, the image file system 1 can be configured to record and reproduce not only compressed image data but also uncompressed image data in real time. Can be configured.
Further, the hard disk device 30₁~ 30_FiveFor example, the image file system 1 can take various configurations, such as replacing a random-access recording device such as an MO device or a DVD device.
[0106]
Second embodiment
The second embodiment of the present invention will be described below.
[0107]
Background of the second embodiment
First, the background of the second embodiment of the present invention will be described with reference to FIG.
11A and 11B show the hard disk device 30.₁~ 30_FiveIt is a figure which illustrates the recording area of the compression image data on (DISC). In FIGS. 11A and 11B, bold lines on the recording medium indicate compressed image data recording areas, (1) to (4) indicate reading orders, and a to d indicate output orders. (Original order).
Arm 38
In FIGS. 11A and 11B, the arm 38 is a hard disk device 30.₁~ 30_FiveAre used to read compressed image data from a recording medium.
[0108]
In the image file system 1 (FIGS. 1 to 3) shown in the first embodiment, compressed image data is interleaved in units of frames and recorded on recording media of a plurality of recording apparatuses. In comparison, the number of seeks that occur during normal reproduction or double-speed reproduction can be greatly reduced, and the compressed image data can be reproduced stably.
[0109]
However, as shown in FIG. 11A, when the compressed image data to be reproduced in this order are recorded in recording areas separated from each other on the hard disk, the arm is included. 38 reads out the compressed image data by accessing the recording areas in the order of (1) to (4) in the order of reproduction (a) to (d), the arm 38 reads the outermost and innermost circumferences of the recording medium. Therefore, there is a possibility that the moving distance and moving time (seek distance, seek time) of the arm 38 become long, and a necessary amount of compressed image data cannot be read within a certain time.
[0110]
The second embodiment of the present invention has been made in view of such a problem, and has improved the operation of the control computer 250 (FIG. 3) of the image file system 1 (FIG. 1) and the most seek distance and By reading the compressed image data by accessing each recording area in the order in which the seek time is shortened ((1) to (4)), a necessary amount of compressed image data is read out within a certain time, and real time An object of the present invention is to enable reliable supply of reproduced image data.
[0111]
Processing of control computer 250 and the like in the second embodiment
The operation of the control computer 250 of the image file system 1 in the second embodiment will be described below. The operations of other components not shown below are the same as those in the first embodiment.
In the second embodiment, the control computer 250 accesses the recording areas in the order in which the seek distance is the shortest, as described above, based on the recording areas managed by the file system 200 when reproducing the compressed image data. .
Note that this portion is shown in the hard disk and the hard disk device 30 for simplicity of explanation.₁~ 30_FiveInstead, a DVD and a DVD device will be described as an example.
A DVD (FIG. 11) is provided with a recording track spirally along the circumferential direction, and the recording track is divided into sectors. A sector number (sector address) is continuously assigned to each of these sectors from the outer peripheral side.
[0112]
Specifically, for example, the sector number 0001h is assigned to the outermost end sector of the recording track, and the sector number 7FFFh is assigned to the innermost end sector of the recording track. Are assigned consecutive sector numbers that increase by one as they go inward.
[0113]
For example, when the sector numbers of the top sectors of the recording areas a to d [FIG. 11 (a), (b)] managed by the file system 200 are, for example, 0100h, 7000h, 0200h, and 6000h, Input / output circuit 20_iWhen the control computer 250 obtains the sector number and data length of the head sector of these recording areas a to d from the file system 200 during reproduction of the compressed image data, for example, the sector number increases monotonously. As shown in FIG. 11 (b), the recording areas a to d are sorted into the recording areas a to d, and the read command [ In FIG. 4B, the number of commands (Num of command; 4 in this case), address (Adress; 0100h, 0200h, 6000h, 7000h) and data length (Length) are set, via the SDRAM control circuit 248 and the like. , The DVD device (hard disk device 30 in the time slot i₁~ 30_Five).
[0114]
The hard disk device 30₁~ 30_FiveIn the hard disk used in the above, the recording tracks are provided concentrically. Similarly, in the same way as in the case of DVD, the control computer 250 sorts the sector addresses of the hard disk as in the case of DVD. A read command can be generated.
[0115]
FIG. 12A shows the hard disk device 30.₁~ 30_FiveFIG. 11 shows the order of the compressed image data portions a to d (FIGS. 11A and 11B) read out from FIG.₁~ 280_FiveThe order of the compressed image data portions a to d (FIGS. 11A and 11B) output from FIG.
[0116]
Hard disk device 30₁~ 30_FiveThe input / output circuit 20_iIn accordance with the read command input from the control computer 250, the compressed image data portions a to d (FIGS. 11A and 11B) are changed to the sector numbers of the first sector as shown in FIG. Based on the order sorted based on the order [1 to 4 shown in FIG. 11 (b), a, c, d, b], the input / output circuit 20 is read in time slot i._iRAM block 280 of₁~ 280_FiveOutput for.
The control computer 250 receives the RAM block 280 via the SDRAM control circuit 248.₁~ 280_FiveAs shown in FIG. 12B, the RAM block 280 is controlled.₁~ 280_FiveThe parts a, c, d, and b of the compressed image data input to are rearranged in the reproduction order (original order) a to d, and the compressed image data is output to the switch circuit 260.
[0117]
As in the first embodiment, the switch circuit 260, the decompression circuit 262, and the encoder circuit 264 deinterleave the input compressed image data, decompress and decode the data, and further encode the D1 or SDI data. Output as a stream.
[0118]
Operation of image file system 1
The operation of the image file system 1 in the second embodiment will be described below with reference to FIG.
FIG. 13 is a flowchart showing the reproduction process (S14) of the image file system 1 in the second embodiment.
[0119]
As shown in FIG. 13, in step 140 (S140), the control computer 250 obtains an instruction (command) specifying the file name of the compressed image data from the system controller 100 via the control line 110.
[0120]
In step 142 (S142), the control computer 250 interprets the command input from the system control apparatus 100. If it is a reproduction command, the process proceeds to S144. If it is a recording command, the control computer 250 proceeds to S160. move on.
[0121]
In step 144 (S 144), the control computer 250 sends the specified compressed image data hard disk device 30 from the file system 200.₁~ 30_FiveRead the physical address, that is, the head sector number and the data length.
[0122]
In step 146 (S146), as described above, the control computer 250 sorts the recording areas based on the sector number of the first sector of the recording area in which each portion of the compressed image data is recorded, and the arm 38 (FIG. 11). ) So that the seek distance is the shortest, and the information is stored.
[0123]
In step 148 (S148), the control computer 250 generates a read command (FIG. 4B) via the SDRAM control circuit 248 and the like so as to reproduce each portion of the compressed image data in the sorted order. Hard disk device 30₁~ 30_FiveOutput for.
[0124]
In step 150 (S150), the hard disk device 30₁~ 30_FiveIn response to the read command, for example, the respective parts of the compressed image data are reproduced in the order shown in FIG. 11B and FIG.₁~ 280_FiveOutput and write to
[0125]
In step 152 (S152), the RAM block 280₁~ 280_FiveWhen 30 frames of data are buffered in the frame memory, the control computer 250 passes the RAM block 280 via the SDRAM control circuit 248.₁~ 280_FiveAre controlled and output to the switch circuit 260 in the order of reproduction as shown in FIG.
[0126]
In step 154 (S154), the control computer 250 determines whether or not the reproduction of the specified compressed image data has been completed. If the reproduction has not been completed, the process returns to the process of S146. The playback process ends.
[0127]
In step 160 (S160), the control computer 250 controls the decoder circuit 220 and the compression circuit 222 to decode the input data stream to generate uncompressed image data, and compress the generated uncompressed image data. The compressed image data is generated by encoding, and the switch circuits 226 and 228 and the RAM block 280 are connected via the SDRAM control circuit 248.₁~ 280_FiveTo control the selected RAM block 280₁~ 280_FiveWrite to an empty bank (frame memory).
[0128]
In step 162 (S162), the control computer 250 passes the SDRAM block 280 via the SDRAM control circuit 248.₁~ 280_FiveThe hard disk device 30₁~ 30_FiveTo output compressed image data.
[0129]
In step 164 (S164), the control computer 250 determines whether or not the recording of the compressed image data has ended. If not, the control computer 250 returns to the process of S160, and if it has ended, the recording process ends.
[0130]
As described above, according to the second embodiment of the present invention, similarly to the first embodiment, the hard disk device 30 is interleaved in byte units.₁~ 30_FiveCompared with the case of recording compressed image data, the number of seeks can be greatly reduced, and the seek distance and seek time can be greatly shortened. Data can be reproduced more reliably. Therefore, according to the second embodiment of the present invention, it is possible to reliably prevent the deterioration of the reproduced image that may occur due to the seek time.
[0131]
The second embodiment can be applied to a recording / reproducing apparatus that performs interleaving in units of bytes in addition to a recording / reproducing apparatus that performs interleaving in units of frames as in the image file system 1.
Note that the second embodiment of the present invention can be modified in the same manner as the first embodiment.
[0132]
【The invention's effect】
As described above, according to the image data recording / reproducing apparatus and method of the present invention, when reproducing a plurality of image data recorded in a discontinuous recording area, the seek distance and the time required for seeking are reduced. Image data can be reproduced with no errors as much as possible, and real-time image data can be reliably reproduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an image file system according to the present invention.
FIG. 2 is a diagram showing a configuration of an input / output control device of the image data recording / reproducing device shown in FIG. 1;
3 is a diagram showing a configuration of an input / output circuit (FIG. 2) of the image file system shown in FIG. 1;
FIGS. 4A to 4C show an instruction S248 output from the input / output circuit to the hard disk device.₁It is a figure which shows the format of (command and status).
FIG. 5 is a diagram showing which number of frames (Frame) included in each second (sec) of compressed image data is recorded in a hard disk device (FIGS. 1 and 2);
FIG. 6 is a diagram showing timings of issuing a read command by the input / output circuit and reproducing the image data by the hard disk device when the image data recording / reproducing apparatus (FIGS. 1 and 2) reproduces the image data.
7 shows the order of frames of compressed image data to be reproduced by the hard disk device (RAM1 to RAM5) when the image data recording / reproducing apparatus (FIGS. 1 and 2) performs normal reproduction (single-speed reproduction) of the image data. It is a figure illustrated.
FIG. 8 is a diagram exemplifying the order of frames of compressed image data reproduced by the hard disk device (RAM1 to RAM5) when the image data recording / reproducing device (FIGS. 1 and 2) reproduces the image data at double speed; is there.
FIG. 9 is a diagram showing the contents of a first process (S10) of a control computer that reads compressed image data from a hard disk device;
FIG. 10 is a diagram illustrating the contents of second processing (S12) of the control computer that reads and outputs compressed image data from a RAM block.
FIGS. 11A and 11B are diagrams illustrating a recording area of compressed image data on a hard disk (DISC) of a hard disk device.
12A shows the order of compressed image data portions a to d [FIGS. 11A and 11B] read from the hard disk device (FIGS. 1 and 2), and FIG. The order of the compressed image data portions a to d (FIGS. 11A and 11B) output from the RAM block is shown.
FIG. 13 is a flowchart showing image file system reproduction processing (S14) in the second embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image file system, 100 ... System control apparatus, 102₁, 102₂... VTR device, 104 ... transmission device, 2 ... image data recording / reproducing device, 18 ... input / output control device, 20₁~ 20₆DESCRIPTION OF SYMBOLS I / O circuit 22 ... Input processing unit 220 ... Decoder circuit 222 ... Compression circuit 224 ... Compression data control circuit 226-230 ... Switch circuit 24 ... Control unit 240 ... Control circuit 242 ... RAM 246 ... ROM, 248 ... SDRAM control circuit, 26 ... output processing unit, 260 ... switch circuit, 262 ... decompression circuit, 264 ... encoder circuit, 28 ... output buffer unit, 280₁~ 280_Five... RAM block, 200 ... file system, 32 ... image data bus, 34 ... downlink bus, 34₁~ 34_Five... bus, 36 ... up bus, 36₁~ 36_Five... Bus, 30 ... Recording device, 30₁~ 30_Five... hard disk devices.

Claims (2)

Image data separating means for separating the image data into a first predetermined number in units of frames;
A data recording / reproducing unit that has a plurality of recording units, and records and reproduces the image data for each frame separated by the image data separation unit in the recording unit;
Image data multiplexing means for multiplexing the image data reproduced by the data reproducing means in units of frames and returning to the order before the image data separating means separates;
Have
When recording the image data, the data recording / reproducing means records the image data of the second predetermined number of adjacent frames in the recording unit that is different for each second predetermined number of frames . At the time of double-speed reproduction of the image data, the second predetermined number of frames from the plurality of recording units to the image data recorded on the plurality of recording units in an order corresponding to double-speed reproduction different from that at the time of single-speed reproduction. Image data recording / reproducing device that reproduces each one . Separating image data into a first predetermined number of frames,
When recording the image data of the first predetermined number of separated frames, the image data of the second predetermined number of adjacent frames is recorded in the recording unit different for each second predetermined number of frames. When the image data recorded in the recording unit is reproduced at double speed, the image data recorded in the plurality of recording units is recorded in the order corresponding to the double-speed reproduction different from that at the time of 1x reproduction. Playing the second predetermined number of frames from the unit ,
An image data recording / reproducing method in which reproduced image data is multiplexed on a frame-by-frame basis and returned to the order before separation by the image data separation means.

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