| Motonari Ito 2007-11-11, 6:56 pm |
| Hi, I have a question about MPEG-2 video compression and
multiplexing.
(Sorry, if it's not the right place)
1. Can transport stream multiplex _any_ valid MPEG-2 video elementary
stream?
2. If (1) is yes, then how can I deal with an elementary stream like
this?
The video elementary stream codes vbv_delay to 0xffff. The bit rate
coded in
the sequence header is low and it takes more than 1 second to fill
vbv_buffer
before decoding the first picture. And, the first picture is very big
(almost same
as the vbv_buffer_size). The stream is MP@H14.
When multiplexing to transport stream, the leak rate between MB and EB
(Rbx) is too small to deliver the first picture within 1 sec. It
violates
the rule defined in ISO/IEC 13818-1 2.4.2.6.
<quote>
The delay of any data through the System Target Decoder buffers shall
be less than or equal to one second except for still picture video
data
and ISO/IEC 14496 streams. Specifically: tdn(j) - t(i) <= 1 second
for
all j, and all bytes i in accessunit An(j).
</quote>
So, my guess is either (1) is false, the video elementary stream is
somehow invalid, or it's a bug of the standard.
Do you have any idea?
Thank you.
|