Method and apparatus for determining a transport bit rate for a Multiprogram transport stream
Method and apparatus for determining a transport bit rate for a multiprogram transport stream (MPTS) is described. In one example, a plurality of transport bit rates is computed for a respective plurality of programs in the MPTS. A highest transport bit rate and a lowest transport bit rate are selected from the plurality of transport bit rates. An average transport bit rate is computed from the highest transport bit rate and the lowest transport bit rate. The average transport bit rate is provided as an initial transport bit rate for the MPTS. Jitter in the MPTS may be compensated using the initial transport bit rate.
1. A method of dejittering a multiprogram transport stream (MPTS), the method comprising:
determining the multiprogram transport stream (MPTS) initial transport bit rate for dejittering a multiprogram transport stream (MPTS), wherein the initial transport bit rate is determined by:
computing program transport bit rates for each of a plurality of programs in the multiprogram transport stream (MPTS) using a processor by performing the following:
extracting a pair of program clock reference (PCR) values from the program using the processor;
determining a number of packets in the multiprogram transport stream (MPTS) between the pair of PCR values using the processor;
determining a number of bits in the number of packets using the processor;
dividing the number of bits by a difference in the pair of PCR values using the processor;
selecting a highest program transport bit rate from the transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS) and a lowest program transport bit rate from program transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS) using the processor;
computing the multiprogram transport stream (MPTS) initial transport bit rate by averaging the highest transport bit rate and the lowest transport bit rate using the processor; and
providing to a de-jittering process for the multiprogram transport stream (MPTS) the initial transport bit rate for the multiprogram transport stream (MPTS) for dejittering the multiprogram transport stream (MPTS).
2. The method of claim 1 , further comprising:
compensating for jitter in the MPTS using the initial transport bit rate.
3. The method of claim 2 , further comprising:
adjusting the initial transport bit rate over time during the compensation of the jitter in the MPTS.
4. The method of claim 3 , wherein the step of adjusting comprises:
computing an updated transport bit rate by counting a number of packets in the MPTS received within a period of time and dividing a number of bits in the number of packets by the period of time in seconds.
5. The method of claim 1 , wherein the MPTS comprises a moving picture experts group (MPEG) transport stream.
6. The method of claim 1 , wherein pairs of the PCR values are extracted from the plurality of programs in parallel.
7. An apparatus for dejittering a multiprogram transport stream (MPTS), comprising:
a processor;
a memory coupled to the processor, the memory including instructions that, when executed by the processor, cause the processor to:
determine a multiprogram transport stream (MPTS) initial transport bit rate for dejittering the multiprogram transport stream (MPTS), wherein the initial transport bit rate is determined by:
compute program transport bit rates for each of a plurality of programs in the multiprogram transport stream (MPTS) using a processor by performing the following:
extracting a pair of program clock reference (PCR) values from the program using the processor;
determining a number of packets in the multiprogram transport stream (MPTS) between the pair of PCR values using the processor;
determining a number of bits in the number of packets using the processor;
dividing the number of bits by a difference in the pair of PCR values using the processor;
select a highest program transport bit rate from the transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS) and a lowest program transport bit rate from program transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS);
compute the multiprogram transport stream (MPTS) initial transport bit rate by averaging the highest transport bit rate and the lowest transport bit rate using the processor; and
provide to a de-jittering process for the MPTS the initial transport bit rate for the multiprogram transport stream (MPTS) for dejittering the multiprogram transport stream (MPTS).
8. The apparatus of claim 7 , wherein the memory further includes instructions that, when executed by the processor, cause the processor to:
compensate for jitter in the MPTS using the initial transport bit rate.
9. The apparatus of claim 8 , wherein the memory further includes instructions that, when executed by the processor, cause the processor to:
adjust the initial transport bit rate over time during the compensation of the jitter in the MPTS.
10. The apparatus of claim 9 , wherein the instructions that, when executed by the processor, cause the processor to adjust the initial transport bit rate over time during the compensation of the jitter in the MPTS comprise instructions, that when executed by the processor, cause the processor to:
compute an updated transport bit rate by counting a number of packets in the MPTS received within a period of time and dividing a number of bits in the number of packets by the period of time in seconds.
11. The apparatus of claim 7 , wherein the MPTS comprises a moving picture experts group (MPEG) transport stream.
12. The apparatus of claim 7 , wherein pairs of the PCR values are extracted from the plurality of programs in parallel.
13. A non-transitory computer readable medium having stored thereon instructions that when executed by a processor cause the processor to perform a method of dejittering a multiprogram transport stream (MPTS), comprising:
determining a multiprogram transport stream (MPTS) initial transport bit rate for dejittering the multiprogram transport stream (MPTS), wherein the initial transport bit rate is determined by:
computing program transport bit rates for each of a plurality of programs in the multiprogram transport stream (MPTS) using a processor by performing the following:
extracting a pair of program clock reference (PCR) values from the program using the processor;
determining a number of packets in the multiprogram transport stream (MPTS) between the pair of PCR values using the processor;
determining a number of bits in the number of packets using the processor;
dividing the number of bits by a difference in the pair of PCR values using the processor;
selecting a highest program transport bit rate from the transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS) and a lowest program transport bit rate from program transport bit rates for the plurality of programs in the multiprogram transport stream (MPTS) using the processor;
computing the multiprogram transport stream (MPTS) initial transport bit rate by averaging the highest transport bit rate and the lowest transport bit rate using the processor; and
providing to a de-jittering process for the multiprogram transport stream (MPTS) the initial transport bit rate for the multiprogram transport stream (MPTS) for dejittering the multiprogram transport stream (MPTS).
14. The non-transitory computer readable medium of claim 13 , further comprising:
compensating for jitter in the MPTS using the initial transport bit rate.
15. The non-transitory computer readable medium of claim 14 , further comprising:
adjusting the initial transport bit rate over time during the compensation of the jitter in the MPTS.
16. The non-transitory computer readable medium of claim 15 , wherein the step of adjusting comprises:
computing an updated transport bit rate by counting a number of packets in the MPTS received within a period of time and dividing a number of bits in the number of packets by the period of time in seconds.
17. The non-transitory computer readable medium of claim 13 , wherein pairs of the PCR values are extracted from the plurality of programs in parallel.