JP2006166034A - Video and sound output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video and sound output device which does not cause the interruption of video images at the time of switching a screen even in the case that the preceding decoding of the video images is performed for video and sound synchronization or the like. <P>SOLUTION: A switch 11 switches whether to supply video data outputted from a video buffer 9 to a frame memory 12 or to supply them to a size conversion part 10, and at the time of the longitudinal/lateral changeover of the screen, the video data outputted from the video buffer 9 for 2 frames from that point of time are supplied to the size conversion part 10. The size conversion part 10 performs the processing of converting longitudinal screen video data to lateral screen video data and the processing of converting the lateral screen video data to the longitudinal screen video data. Converted data outputted from the size conversion part 10 are stored in the frame memory 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a video / audio output apparatus such as a digital broadcast receiving apparatus for receiving a digital broadcast.

  Conventionally, a mobile phone having a TV function for receiving terrestrial analog broadcasting is known (see Patent Document 1). Also, terrestrial digital broadcasting (one-segment broadcasting) is scheduled for portable devices or mobile devices, and a mobile phone with a TV capable of receiving this terrestrial digital broadcasting will be proposed. In such a mobile phone with TV, switching between video display on a vertical screen and video display on a horizontal screen can be considered.

  FIG. 5 is a block diagram showing a conventional circuit configuration for digital broadcast reception. In the digital broadcast reception, the broadcast wave of the channel selected from the radio waves received by the antenna 1 is demodulated by the tuner 2, and the video ES (elementary stream) and the audio ES (demultiplexer) 3 are demultiplexed by the demultiplexer 3. Elementary streams) and stored in buffers 4 and 5, respectively. Then, the decoders 6 and 7 perform decoding, and the video and audio data are output in accordance with an instruction from the AV synchronization controller 8. Here, it is common to decode video in advance for video / audio synchronized playback and video rearrangement. In particular, in a decoding configuration where real-time decoding is difficult, such as a software decoder, the preceding decoding of the video is effective. Video data obtained by this preceding decoding is stored in the video buffer 9.

Further, as described above, when switching between video display on a vertical screen and video display on a horizontal screen (hereinafter simply referred to as screen switching), it is necessary to convert the size of the video data. This size conversion is performed by the video decoder 7. Will be done. Further, the 90 ° rotation process of the video at the time of switching the screen is performed in the data writing process to the frame memory provided in the subsequent stage of the video buffer 9 or the data reading process from the frame memory.
JP 2003-1111040 A

  However, the above-described conventional circuit configuration has a drawback in that when the screen is switched, it is necessary to discard the video data obtained by the preceding decoding, so that the video is interrupted when the screen is switched.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a video / audio output device in which video is not interrupted even when screen switching is performed.

  In order to solve the above-described problem, the video / audio output device of the present invention decodes a video stream one frame or a plurality of frames ahead of the audio, stores the video data obtained by the preceding decoding in a buffer, In the video / audio output device configured to generate the video data according to the vertical arrangement and horizontal arrangement of the screen, when the video data read from the buffer is for a vertical screen, the video data is enlarged, while for the horizontal screen A size conversion unit that performs reduction processing at a time, selection means for selecting and outputting either the video data output from the buffer or the size-converted video data, and switching between the vertical arrangement and the horizontal arrangement of the screen Sometimes, the control means for causing the selection means to select the size-converted video data for one frame or several frames. Characterized by comprising a and.

  With the above configuration, even when one or more frames are decoded in advance for video / audio synchronization or the like, the size-converted video data for the several frames at the time of switching between the vertical arrangement and the horizontal arrangement of the screen Is output immediately, so that even if the screen is switched, the video is not interrupted.

  The video / audio output device having the above-described configuration may include a broadcast receiving unit that receives terrestrial digital broadcasts, and may be configured to generate a video stream and an audio stream from the received broadcast wave. In addition, the video / audio output device having these configurations may include a communication function unit and generate a video stream and an audio stream from a signal received through communication.

  Further, the video / audio output device having these configurations may be configured as a portable type or a mobile type.

  As described above, according to the present invention, there is an effect that the video is not interrupted when the screen is switched even when the video is decoded in advance for video / audio synchronization or the like.

  A video / audio output apparatus according to an embodiment of the present invention will be described below with reference to FIGS. Here, a mobile phone with a TV (terrestrial digital broadcast receiving function) is illustrated as the video / audio output device. For convenience of explanation, in FIG. 2, the same reference numerals are given to components common to the components in FIG. 5.

  FIG. 1 is a block diagram showing a mobile phone 100 with a TV. This portable cellular phone with TV 100 includes a telephone function unit 30 and a digital broadcast receiving unit 20. The telephone function unit 30 includes a control unit 31, a wireless communication unit 32, a voice processing unit 33, a memory unit 34, a key input unit (operation unit) 35, a display unit (for example, a liquid crystal panel) 36, data And a processing unit 37. The voice signal received in the normal telephone process is given to the speaker 38 via the voice processing unit 33, while the voice uttered by the user is converted into a voice signal by the microphone 39 and subjected to processing such as amplification by the voice processing unit 33. The audio signal is sent out by the wireless communication unit 32. The data processing unit 37 performs processing on the received packet. The wireless communication unit 32 performs voice and data transmission / reception processing and predetermined protocol processing (transmission time processing and reception time processing) with the base station 60. The control unit 31 performs overall control in the telephone function unit 30 and performs processing for cooperation with the digital broadcast receiving unit 20. For example, as a basic process, when the TV function activation key is turned on in the key input unit 35, an ON command is given to the digital broadcast receiving unit 20, and the video output from the digital broadcast receiving unit 20 is displayed on the display unit 36. A process of giving the digital broadcast receiving unit 20 a channel selection command with the number as a channel number when the numeric keypad of the key input unit 35 is operated is performed.

  Next, the digital broadcast receiver 20 will be described with reference to FIG. The terrestrial antenna 1 gives the received signal to the terrestrial digital tuner 2. The terrestrial digital tuner 2 extracts a signal having a specific frequency from the high-frequency digital modulation signal including video / audio data. The terrestrial digital tuner 2 includes a demodulation circuit, a deinterleave circuit, an error correction circuit, etc., and demodulates the selected digital modulation signal to output a transport stream.

  The demultiplexing unit (demultiplexer) 3 converts the transport stream into an IEEE H.264 standard. H.264 video stream, audio stream, PSI / SI (Program Specific Information / Service Information), broadcast information (region identifier, service type, broadcast station identification, service number, remote control key ID), etc. The demultiplexer 3 supplies the video elementary stream to the video ES buffer 5, supplies the audio elementary stream to the audio ES buffer 4, and supplies PSI / SI and broadcast information to the CPU 13.

  The video decoder 7 reads the encoded signal from the video ES buffer 5, decodes the encoded signal to obtain a quantization coefficient and a motion vector, and performs motion compensation control based on inverse DCT transform and motion vector. Then, the video decoder 7 generates and outputs video data for a vertical screen or video data for a horizontal screen. The CPU 13 gives a command to the video decoder 7 to generate the video data for the vertical screen or to generate the video data for the horizontal screen. The CPU 13 outputs the instruction when it receives information about screen switching (key operation information) by a user operation via the control unit 31. The audio decoder 6 reads the encoded signal from the audio ES buffer 4 and decodes the encoded signal to generate audio data. The AV synchronization controller 8 controls the output timing of video data and audio data.

  Video data output from the video decoder 7 is stored in a video buffer 9. In this embodiment, video data for two frames is stored in the video buffer 9. From the video buffer 9, it is read from the previously decoded video data (frame). The read video data is supplied to the switch 11.

  The switch 11 switches whether the video data output from the video buffer 9 is supplied to the frame memory 12 or the size converter 10. A command to which video data is to be supplied is given from the CPU 13 to the switch 11. When the screen switching occurs, the CPU 13 switches the switch 11 so that the video data output from the video buffer 9 is supplied to the size conversion unit 10 for two frames from that point in time, and the video data for the two frames. Is output, the switch 11 is switched so that the output video data from the video buffer 9 is supplied to the frame memory 12 as usual.

  When the video data input from the switch 11 is vertical screen video data, the size conversion unit 10 expands the video data to the horizontal screen size (pixel interpolation processing). On the other hand, when the input video data is horizontal screen video data, the video data is reduced to a size that fits in the horizontal screen (pixel thinning process). As shown in FIG. 4, the size of the video in the horizontal screen display in FIG. 4B is larger than that in the vertical screen display in FIG. A command to perform the reduction process or the enlargement process is given from the CPU 13 to the size conversion unit 10. The conversion data output from the size conversion unit 10 is stored in the frame memory 12.

  The 90 ° rotation process of the video at the time of switching the screen is performed in the data writing process to the frame memory 12 or the data reading process from the frame memory 12. The video data read from the frame memory 12 is supplied to a liquid crystal display panel (screen) (not shown).

  FIG. 3 is an explanatory diagram showing the relationship between the video decoding frame and the displayed frame at the time of screen switching. FIG. 3A shows the case of switching from the vertical screen to the horizontal screen. (B) shows the case of switching from a horizontal screen to a vertical screen. As described above, video data for two frames is stored in the video buffer 9 for video / audio synchronization and the like. Accordingly, two frame numbers are being decoded before the display frame number shown in the figure. After the screen switching, the video decoder 7 sequentially executes the processing for the frames as number 1, number 2, number 3,. On the other hand, in the video display, the frames of the numbers “10” and “11” in the video buffer 9 (vertical screen or horizontal screen video data) are used, and these video data are enlarged or converted to a horizontal screen. Thus, the video data obtained by the reduction processing is immediately supplied to the liquid crystal display panel (screen). That is, even when screen switching occurs, the video is displayed without interruption.

  In the above example, a mobile phone with a TV function has been described, but it may be configured as a portable or mobile digital broadcast receiving apparatus. In addition, in the case of having a telephone function, it is possible to generate a video stream and an audio stream from a signal received through communication. It can be carried out. A desktop display can also be switched between a vertical arrangement and a horizontal arrangement, and is not limited to a portable type or a mobile type. The screen switching information is key operation information by the user. However, for example, a tilt sensor may be provided, and the CPU may determine screen switching (vertical / horizontal of the screen) based on the output of the tilt sensor.

It is the block diagram which showed the mobile telephone with TV of embodiment of this invention. It is the block diagram which showed the digital broadcast receiving part of the mobile telephone with TV of embodiment of this invention. FIG. 4A is an explanatory diagram showing the processing content when switching from the vertical screen to the horizontal screen, and FIG. 4B is an explanatory diagram showing the processing content when switching from the horizontal screen to the vertical screen. is there. FIG. 4A is an explanatory diagram showing a vertical screen display in a mobile phone with TV, and FIG. 4B is an explanatory diagram showing a horizontal screen display. It is the block diagram which showed the conventional digital broadcast receiver.

Explanation of symbols

7 Video decoder 9 Video buffer 10 Size converter 11 Switch 12 Frame memory 20 Digital broadcast receiver 30 Telephone function unit 31 Control unit 32 Wireless communication unit

Claims (4)

The video stream is decoded one frame or a plurality of frames ahead of the audio, the video data obtained by the preceding decoding is stored in a buffer, and the video data is generated according to the vertical arrangement and horizontal arrangement of the screen. In the video / audio output device configured as described above, when the video data read from the buffer is for a vertical screen, it is enlarged, and when it is for a horizontal screen, a size conversion unit that performs a reduction process is output from the buffer. Selection means for selecting and outputting either video data or the size-converted video data, and the size-converted video data for the one frame or several frames when the vertical layout and horizontal layout of the screen are switched. And a control unit that causes the selection unit to select one of the two. 2. The video / audio output device according to claim 1, further comprising a broadcast receiving unit that receives a terrestrial digital broadcast, and configured to generate a video stream and an audio stream from the received broadcast wave. apparatus. 3. The video / audio output device according to claim 1, further comprising a communication function unit configured to generate a video stream and an audio stream from a signal received through communication. apparatus. 4. The video / audio output apparatus according to claim 1, wherein the video / audio output apparatus is configured as a portable type or a mobile type.

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