Transport stream generating device and method, and program transmission device

• US 6,542,518 B1
• Filed: 11/23/1998
• Issued: 04/01/2003
• Est. Priority Date: 03/25/1997
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH, Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Miyazawa, Satoshi
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/194,264
• Time in Patent Office: 1,590 Days
• Field of Search: 370/458, 370/462, 370/465, 370/468, 370/537, 370/538, 370/474, 370/486, 370/487, 370/493, 370/498, 348/423.1
• US Class Current: 370/468
• CPC Class Codes: H04N 21/23655 Statistical multiplexing, e.g. by controlling the encoder to alter its bitrate to optimize the bandwidth utilization
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/2401 Monitoring of the client buffer

Abstract

Each of the data amount of a video stream multiplexed in one video frame period and the data amount of an audio stream multiplexed in a predetermined period is almost constant in any video frame period. The data amount of a transport stream generated in one video frame period is almost constant in any video frame period. In addition, corresponding to a target video encoding rate and a target audio encoding rate, schedule data for multiplexing a video stream and an audio stream is generated. Corresponding to the schedule data, a video stream and an audio stream are multiplexed and output as a transport stream to a decoding unit so that an SDT buffer of the decoding unit does not overflow.

Claims

1. A transport stream generating apparatus for generating a transport stream for transmitting source video data and source audio data, comprising:

encoding means for encoding source video data and source audio data corresponding to an assigned video encoding rate and an assigned audio encoding rate so as to generate an encoded video stream and an encoded audio stream, respectively;

multiplexing means for multiplexing the encoded video stream and the encoded audio stream in each of at least one predetermined period;

transport stream generating means for generating the transport stream with the multiplexed stream of the video stream and the audio stream;

controlling means for controlling said encoding means, said multiplexing means, and said transport stream generating means so that each of a data amount of the encoded video stream multiplexed in a predetermined period and a data amount of the encoded audio stream multiplexed in the predetermined period is near constant for all predetermined periods;

the predetermined period being one video frame period;

said controlling means comprising means for generating a schedule corresponding to the assigned video encoding rate and the assigned audio encoding rate so as to multiplex the encoded video stream and the encoded audio stream;

said controlling means controlling said multiplexing means and said transport stream generating means so as to perform a multiplexing process corresponding to the schedule for all predetermined periods; and

said controlling means calculating the data amount of the encoded video stream transmitted in one video frame period corresponding to the assigned video encoding rate, calculating the data amount of the encoded audio stream transmitted in one audio frame period corresponding to the assigned audio encoding rate, and generating the schedule corresponding to the data amount of the calculated encoded video stream and the data amount of the calculated audio stream.

2. The transport stream generating apparatus as set forth in claim 1, further comprising:

video encoder buffering means for buffering the encoded video stream outputted from said encoding means; and

audio encoder buffering means for buffering the encoded audio stream outputted from said encoding means;

wherein, when a cumulative data amount of a remaining data amount of the video encoder buffering means as an (n-1)th transport stream of the encoded video stream in an (n-1)th video frame period and the data amount of the encoded video stream outputted from said encoding means as the encoded video stream in an n-th video frame period is larger than the data amount of the encoded video stream of one transport stream defined in the schedule, said controlling means controls said multiplexing means and said transport stream generating means so as to multiplex the remaining data in the n-th video frame period and the first half of the data of the encoded video stream in the (n+1)th video frame period as a transport stream in the n-th video frame period and multiplex the remaining data of the encoded video stream in the n-th video frame period as a transport stream in the (n+1)th video frame period.

3. The transport stream generating apparatus as set forth in claim 1, further comprising:

video encoder buffering means for buffering the encoded video stream outputted from said encoding means; and

audio encoder buffering means for buffering the encoded audio stream outputted from said encoding means, wherein;

said controlling means controls a data amount of the encoded video stream from the video encoder buffering means in the current video frame period corresponding to a data amount of video data that remains in the video encoder buffering means as a result of a transport stream generating process in a preceding video frame period and corresponding to the data amount of an encoded video stream from said encoding means in the current video frame period; and

said controlling means controls the data amount of the encoded audio stream from the audio encoder buffering means in the current video frame period corresponding to the data amount of audio data that remains in the audio encoder buffering means as the result of a transport stream generating process in the preceding video frame period and corresponding to the data amount of an encoded audio stream from said encoding means in the current video frame period.

4. A transport stream generating apparatus for generating a transport stream for transmitting source video data and source audio data, comprising:

encoding means for encoding source video data and source audio data corresponding to an assigned video encoding rate and an assigned audio encoding rate so as to generate an encoded video stream and an encoded audio stream, respectively;

multiplexing means for multiplexing the encoded video stream and the encoded audio stream in each of at least one predetermined period;

transport stream generating means for generating the transport stream with the multiplexed stream of the video stream and the audio stream;

controlling means for controlling said encoding means, said multiplexing means, and said transport stream generating means so that each of a data amount of the encoded video stream multiplexed in a predetermined period and a data amount of the encoded audio stream multiplexed in the predetermined period is near constant for all predetermined periods;

the predetermined period being one video frame period;

said controlling means comprising means for generating a schedule corresponding to the assigned video encoding rate and the assigned audio encoding rate so as to multiplex the encoded video stream and the encoded audio stream;

said controlling means controlling said multiplexing means and said transport stream generating means so as to perform a multiplexing process corresponding to the schedule for all predetermined periods; and

said controlling means calculating a number of transport packets necessary for transmitting the encoded video stream corresponding to the assigned video encoding rate, calculating a number of transport packets necessary for transmitting the encoded audio stream corresponding to the assigned audio encoding rate, and generating the schedule corresponding to a number of transport packets for the encoded video stream and a number of the transport packets for the encoded audio stream.

5. The transport stream generating apparatus as set forth in claim 4, further comprising:

video encoder buffering means for buffering the encoded video stream from said encoding means; and

audio encoder buffering means for buffering the encoded audio stream from said encoding means,

wherein when a cumulative data amount of a remaining data amount of the video encoder buffering means as an (n-1)th transport stream of an encoded video stream in an (n-1)th video frame period and a data amount of an encoded video stream that is output from said encoding means as an encoded video stream in an n-th video frame period is larger than a data amount of an encoded video stream of one transport stream defined in the schedule, said controlling means controls said multiplexing means and said transport stream generating means so as to multiplex remaining data in the (n-1)th video frame period and the first half of the data of the encoded video stream in the n-th video frame period as a transport stream in the n-th video frame period and multiplex the remaining data of the encoded video stream in the n-th video frame period as a transport stream in the (n+1)th video frame period.

6. The transport stream generating apparatus as set forth in claim 4, further comprising:

video encoder buffering means for buffering the encoded video stream outputted from said encoding means; and

audio encoder buffering means for buffering the encoded audio stream outputted from said encoding means, wherein;

said controlling means controls a data amount of the encoded video stream from the video encoder buffering means in the current video frame period corresponding to a data amount of video data that remains in the video encoder buffering means as a result of a transport stream generating process in a preceding video frame period and corresponding to the data amount of an encoded video stream from said encoding means in the current video frame period; and

said controlling means controls the data amount of the encoded audio stream from the audio encoder buffering means in the current video frame period corresponding to the data amount of audio data that remains in the audio encoder buffering means as the result of a transport stream generating process in the preceding video frame period and corresponding to the data amount of an encoded audio stream from said encoding means in the current video frame period.

7. A transport stream generating method of generating a transport stream for transmitting source video data and source audio data, comprising the steps of:

an encoding step of encoding source video data and source audio data corresponding to an assigned video encoding rate and an assigned audio encoding rate so as to generate an encoded video stream and an encoded audio stream, respectively;

a schedule generating step of generating a schedule corresponding to the assigned video encoding rate and the assigned audio encoding rate so as to multiplex the encoded video stream and the encoded audio stream;

a multiplexing step of multiplexing the encoded video stream and the encoded audio stream in each of at least one predetermined period in accordance with the generated schedule;

a predetermined period being one video frame period; and

a transport stream generating step of generating the transport stream with the multiplexed stream of the video stream and the audio stream;

the schedule generating step being performed by calculating a data amount of the encoded video stream transmitted in one video frame period corresponding to the assigned video encoding rate, calculating a data amount of the encoded audio stream transmitted in one audio frame period corresponding to the assigned audio encoding rate, and generating the schedule corresponding to the data amount of the calculated encoded video stream and the data amount of the calculated encoded audio stream.

8. The transport stream generating method as set forth in claim 7, wherein when a cumulative data amount of a remaining data amount in an encoder buffer for an (n-1)th transport stream of an encoded video stream in an (n-1)th video frame period and a data amount of an encoded video stream as an encoded video stream in an n-th video frame period is larger than a data amount of an encoded video stream of one transport stream defined in the schedule, the multiplexing step is performed by multiplexing remaining data in the (n-1)th video frame period and the first half of the data of the encoded video stream in the n-th video frame period as a transport stream in the n-th video frame period and multiplexing the remaining data of the encoded video stream in the n-th video frame period as a transport stream in the (n+1)th video frame period.

9. The transport stream generating method as set forth in claim 7, wherein the multiplexing step is performed by controlling the data amount of the encoded video stream from a video encoder buffer in the current video frame period corresponding to a data amount of video data that remains in the video encoder buffer as a result of a transport stream generating process in a preceding video frame period and corresponding to the data amount of an encoded video stream in the current video frame period, and controlling the data amount of the encoded audio stream from an audio encoder buffer in the current video frame period corresponding to a data amount of audio data that remains in the audio encoder buffer as the result of a transport stream generating process in the preceding video frame period and corresponding to the data amount of an encoded audio stream in the current video frame period.

10. A transport stream generating method of generating a transport stream for transmitting source video data and source audio data, comprising the steps of:

an encoding step of encoding source video data and source audio data corresponding to an assigned video encoding rate and an assigned audio encoding rate so as to generate an encoded video stream and an encoded audio stream, respectively;

a schedule generating step of generating a schedule corresponding to the assigned video encoding rate and the assigned audio encoding rate so as to multiplex the encoded video stream and the encoded audio stream;

a multiplexing step of multiplexing the encoded video stream and the encoded audio stream in each of at least one predetermined period in accordance with the generated schedule;

a predetermined period being one video frame period; and

a transport stream generating step of generating the transport stream with the multiplexed stream of the video stream and the audio stream;

the schedule generating step being performed by calculating a number of transport packets necessary for transmitting the encoded video stream corresponding to the assigned video encoding rate, calculating a number of transport packets necessary for transmitting the encoded audio stream corresponding to the assigned audio encoding rate, and generating the schedule corresponding to the number of transport packets for the encoded video stream and the number of the transport packets for the encoded audio stream.