JP3770001B2 - Digital audio signal transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for transmitting a digital audio signal interleaved with a video signal that has been encoded with high efficiency in a digital interface.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an apparatus described in Japanese Patent Laid-Open No. 3-141079 is known as a playback apparatus for a high-efficiency encoded video signal and an interleaved digital audio signal.
[0003]
FIG. 3 shows the structure of a conventional reproducing apparatus, in which 101 is a cylinder unit, 102 is a reproduction signal processing circuit, 103 is a memory circuit, 104 is an interpolation filter, 105 is a tape drive circuit, 106 is a frame update determination circuit, 107 Is a memory control circuit, and 3 is a system control unit. These operations will be described below.
[0004]
The system control unit 3 receives the operation key input j, and outputs the tape running speed information g to the tape drive circuit 105 that drives the tape according to the operation instruction. The tape drive circuit 105 causes the tape to run by the tape drive output i. The cylinder part output a reproduced by the cylinder part 101 is subjected to error correction, rearrangement processing and the like in the reproduction signal processing circuit 102, and then separated into a video signal k and an audio signal b and outputted. At this time, the reproduction signal processing circuit 102 reads the track number from the cylinder part output a and outputs the track number e to the frame update determination circuit 106. The frame update determination circuit 106 detects the change of the frame. The frame update determination circuit 106 creates a frame end pulse f synchronized with the frame from the detection result of the frame change, and outputs it to the memory control circuit 107. The memory control circuit 107 controls the memory circuit 103 by outputting a memory control signal h. The memory circuit 103 controls writing of the audio signal b by the memory control signal h. The interpolation filter 104 interpolates the audio signal c read from the memory circuit 103 according to the tape running speed information g. The video signal k output from the reproduction signal processing circuit 102 and the audio signal d output from the interpolation filter 104 are output as the output of the reproduction apparatus.
[0005]
Further, a means described in Japanese Patent Laid-Open No. 7-73586 is known as means for transmitting a digital audio signal interleaved in a conventional digital interface. There is SMPTE305M as a digital interface standard for high-efficiency encoded video signals. A digital interface for transmitting video signals based on this standard will be described.
[0006]
FIG. 4 shows the configuration of a serial data transport interface having the structure of a conventional digital audio signal transmission method. In the playback unit and playback signal processing circuit 1, the playback speed and playback direction information indicated by the system control unit 3 is read from the recording medium. Playback and special playback processing are performed. The video signal changeover switch 2 selects the output signal from the reproduction unit and reproduction signal processing circuit 1 and the output signal of the serial data receiving device 201, and the selected signal is the speed and direction information changing device 4, the audio signal reproducing device 8 , And output to the video signal reproducing device 9. The signal reproduced by the reproduction unit and the reproduction signal processing circuit 1 and the signal received by the serial data receiving device 201 are necessary for reproducing a highly efficient encoded video signal and an interleaved audio signal, video and audio signal. VAUX and AAUX are included as system data.
[0007]
Here, a description will be given using AUX defined in SMPTE 314M.
[0008]
FIG. 7 is a mapping diagram of the AAUX source control pack, and FIG. 8 is a mapping diagram of the VAUX source control pack. The AAUX source control pack includes SPEED (7 bits) as information indicating the playback speed of the video signal and DRF (1 bit) as information indicating the playback direction. The speed information expresses the speed from 0 to 1 × speed in 1/120 steps (PAL is 1/100 steps in NTSC time). The VAUX source control pack includes an FC indicating frame switching of a video signal, an FF for controlling a field to be reproduced, and an FS. FC is set to “0” if the video signal to be output from the transmission side is the same as the signal output one frame before, and “1” if the video signal is different from the signal output before the output. FF and FS are information for controlling the video signal in field units at the time of monitor output, and the reproduction side transmits these information together with the video and audio signals. FIG. 5 shows the relationship between the monitor output video, audio signal, serial data output video, audio signal, FC, FF, FS, and frame end pulse during normal playback.
[0009]
The speed and direction information switching device 4 uses the playback speed and playback direction information in the source control pack in the AAUX of the input signal as a special sound based on the playback speed and playback direction information from the playback unit and playback signal processing circuit 1. If it is a reproducible range, it is replaced with information from the playback unit and the playback signal processing circuit 1, and if it is a speed range where audio playback processing is impossible, it is replaced with invalid speed information and output to the serial data transmission device 7. The serial data receiving apparatus 201 depackets the packetized input signal and outputs video and audio signals to the video signal changeover switch 2. The serial data transmission device 7 packetizes the signal selected by the video signal selector switch 2 and outputs serial data in a form conforming to SMPTE 305M.
[0010]
Also, the audio signal reproduction device 8 which is an audio signal monitor means performs deinterleave processing of the input audio signal using the reproduction speed and reproduction direction information from the reproduction unit and reproduction signal processing circuit 1 and the frame end pulse. , Perform audio output. In the video signal reproduction device 9 which is a video signal monitoring means, the reproduction speed and reproduction direction information from the reproduction unit and the reproduction signal processing circuit 1 and the information indicating the field output order are used, and the input video signal is efficiently decoded. Process and output video.
[0011]
[Problems to be solved by the invention]
Currently, a digital audio signal transmission apparatus is required to receive an audio signal specially reproduced by a transmission apparatus on the transmission side and monitor the specially reproduced audio from the received signal.
[0012]
However, in the above-mentioned conventional example, since the reproduction process of the input serial data is performed by the frame end pulse f from the frame update determination circuit 106 in the reproduction unit and the reproduction signal processing circuit 1, serial data input at the time of special reproduction is performed. There is a problem that a sound output obtained by performing special reproduction processing normally cannot be obtained. A state in which the sound at the time of special reproduction serial data input cannot be monitored normally will be described with reference to FIG. FIG. 6 shows a monitor output diagram when serial data for 0.5 × speed special reproduction is input. The signal received by the digital interface is a compressed video signal for one frame and an interleaved audio signal for one frame. For transmission of the reproduction signal, in addition to the signal for one frame of the video and audio, a signal indicating the reproduction state of the video and audio is also transmitted. However, the conventional configuration is not configured to restore the signal necessary for special playback or adjust the timing of the processing of the audio signal playback device 8 from the information indicating the playback state. The playback unit and the playback signal processing circuit 1 The reproduction processing is performed by the reproduction speed and reproduction direction information from the frame and the frame end pulse. If the frame end pulse from the frame update determination circuit 106 is the same as that during normal playback when the special playback signal is received, the sound that was originally subjected to slow playback processing over two frames is output when the special playback signal is received during 0.5 × speed playback. However, in the current configuration, the sound that has been processed during normal playback is output repeatedly for two frames.
[0013]
An object of the present invention is to receive a specially reproduced signal and monitor the specially reproduced sound from the received signal.
[0014]
[Means for Solving the Problems]
In order to solve this problem, the present invention switches frames from video data of externally input serial data, system data indicating the state of audio signals, speed information and playback direction information, information indicating the output order of fields, and the like. After detecting, creating a frame end pulse that matches the input signal, and adjusting the timing, it is configured to be used during audio signal reproduction processing.
[0015]
As a result, even when serial data for special reproduction is input, special reception processing suitable for the input signal can be performed on the receiving side, and normal specially reproduced sound can be monitored.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention receives digital serial data including an externally input video signal transmitted in units of frames and an interleaved audio signal, and reproduces the input signal. Data receiving means for outputting speed and reproduction direction information , information indicating the field output order, and information indicating the frame switching output from the data receiving means, and detecting the switching of the frame of the video signal of the input signal. Frame end detection means for outputting the frame end pulse, the frame end pulse from the frame end detection means, the reproduction speed and reproduction direction information, and the audio input from the data reception means using the information indicating the field output order. Audio signal re-interleaving and slow playback processing Means a digital audio signal transmission apparatus characterized by comprising a video signal reproducing means for output order by using a signal indicating perform the reproduction process of the video signal input from the data receiving means of the field, Even when serial data at the time of special reproduction is input, special reception processing suitable for the input signal can be performed on the receiving side, and normal special reproduction sound can be monitored.
[0017]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
(Embodiment 1)
FIG. 1 shows a digital audio signal transmission apparatus capable of monitoring the special reproduction sound on the receiving side when receiving the specially reproduced serial data, and receiving the serial data receiving the specially reproduced serial data in FIG. The device 5 depackets the input serial data and outputs the video and audio signals to the video signal changeover switch 2, and at the same time, the playback speed and playback direction information from the VAUX and AAUX of the system data in the serial data, the output order of the fields And information indicating frame switching are detected and output to the frame end detection device 6. The frame end detection device 6 detects frame switching from the input information indicating frame switching, generates a frame end pulse, and outputs the frame end pulse to the control signal switching switch 10. The frame end pulse can be generated by detecting frame switching from the FC in the received signal and using speed information. FIG. 2 is a diagram showing an example of a frame end pulse necessary for memory control for receiving a 0.5 × speed reproduction signal and restoring the special reproduction sound. By using FC, FF, and FS detected from the input signal, a frame end pulse is generated, and the timing adjustment is performed as shown in the figure, so that the same signal as the frame end pulse output from the playback unit and playback signal processing circuit 1 during special playback. It is possible to obtain
[0019]
The video signal selector switch 2 selects and outputs an input signal from the reproduction unit and the reproduction signal processing circuit 1 and an input signal from the serial data receiving device 5, and inputs from the serial data receiving device 5 when recording and monitoring the input signal. A signal is selected, and the selected signal is output to the speed and direction information changing device 4, the video signal reproducing device 9 and the audio signal reproducing device 8. In the control signal changeover switch 10, the playback speed and playback direction information used for playback processing from the playback unit and playback signal processing circuit 1, information indicating the output order of fields, the frame update determination circuit 106 in the playback unit and playback signal processing circuit 1 Frame end pulse and frame end detection device 6, the playback speed and playback direction information detected by the serial data receiving device 5 from the external input signal, information indicating the output order of the field, and the frame created by the frame end detection device 6 An end pulse is input. When recording and monitoring the input signal, the signal from the frame end detection device 6 is selected and output to the speed and direction information changing device 4, the audio signal reproduction device 8, and the video signal reproduction device 9. The speed and direction information changing device 4, the audio signal reproducing device 8, the video signal reproducing device 9, and the serial data transmitting device 7 perform the same processing as when special reproduction is performed by the reproducing unit and the reproduction signal processing circuit 1.
[0020]
【The invention's effect】
As described above, in the present embodiment, the reproduction speed and reproduction direction information, the information indicating the output order of the field, and the information indicating the frame switching are detected from the serial signal received at the time of receiving the specially reproduced serial data. The frame end pulse necessary for audio memory control at the time of reproduction is recreated, and the frame end pulse regenerated at the time of the audio reproduction process is switched and used, so that the audio at the special reproduction can be monitored on the receiving side. In addition, by sharing a device necessary for the conventional special reproduction processing, it is possible to realize the special reproduction processing of the received signal with a minimum number of circuits.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a digital audio signal transmission apparatus according to a first embodiment of the present invention. FIG. 2 is a slow view at the time of 0.5 × special playback of the digital audio signal transmission apparatus according to the first embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of a conventional playback device. FIG. 4 is a block diagram showing the configuration of a conventional digital audio signal transmission device. FIG. 6 is a diagram illustrating a specific change of a signal necessary for slow playback processing during normal playback of a conventional digital audio signal playback device. FIG. 6 shows slow playback during 0.5 × special playback of a conventional digital audio signal playback device. FIG. 7 is a diagram illustrating a specific change in a signal necessary for processing. FIG. 7 is a mapping diagram of an AAUX source control pack defined in SMPTE 314M. Mapping diagram of a source control pack of VAUX defined in 314M [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Reproduction | regeneration part and reproduction | regeneration signal processing circuit 2 Changeover switch 3 System control part 4 Speed and direction information changer 5 Serial data receiver 6 Frame end detector 7 Serial data transmitter 8 Audio signal reproducer 9 Video signal reproducer 10 Changeover switch 103 Memory Circuit 106 Frame Update Determination Circuit 107 Memory Control Circuit

Claims (1)

Receives digital data including an externally input video signal transmitted in frame units and an interleaved audio signal, and includes information indicating playback speed and playback direction information and field output order included in the input signal. Data receiving means for outputting;
A frame end detection means for detecting a frame change of a video signal of an input signal from information indicating a frame change outputted from the data receiving means, and outputting a detection result as a frame end pulse;
An audio signal for performing deinterleaving processing and slow playback processing of the audio signal input from the data receiving means using the frame end pulse from the frame end detecting means, the playback speed and playback direction information, and the information indicating the field output order. Reproduction means,
A digital audio signal transmission apparatus comprising: a video signal reproduction unit that performs a reproduction process of the video signal input from the data reception unit using a signal indicating the output order of the fields.

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