mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-27 10:40:34 +00:00
82cf691a75
Original commit message from CVS: Moved from gst-plugins/ext/mplex/. See that directory for older changelogs.
67 lines
2.8 KiB
Text
67 lines
2.8 KiB
Text
//////////////////////////////////////////////////////////////////////////
|
|
// //
|
|
// INSTRUCTIONS FOR MPLEX - THE MPEG1/SYSTEMS MULTIPLEXER //
|
|
// //
|
|
//////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
Please note that I do not have a comprehensive instruction manual for this
|
|
release. I suggest you try the program out with some default values and
|
|
learn something more about ISO/IEC 11172-1 (aka MPEG1/Systems).
|
|
|
|
For those of you that can read *German*, you can download a postscript
|
|
paper discussing implementation and problems of this software, with
|
|
introductions to MPEG1/Audio, MPEG1/Video and MPEG1/Systems.
|
|
You should find the paper with the same distribution you got this
|
|
program from.
|
|
|
|
If not, you should find the postscript version of this 40-page paper
|
|
on
|
|
|
|
ftp.informatik.tu-muenchen.de in /pub/comp/graphics/mpeg/mplex
|
|
|
|
(121822 bytes, Jun 30 , 1994 , mpeg_systems_paper_0.99.ps.gz)
|
|
|
|
If you have any questions you cannot figure out by running the
|
|
program, feel free to ask me.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
One more thing that might save me many emails:
|
|
|
|
when asked about the startup packet delay, try something like
|
|
half the video buffer size divided by your sector size. Say you
|
|
have a 40 kByte video buffer and a 2324 Byte Sector size, then
|
|
a startup delay of 8 sectors will work just fine.
|
|
|
|
What does the above parameter mean?
|
|
|
|
Normally, the Decoding/Presentation Time Stamp of the first access
|
|
unit is set to the clock value that will happen exactly after the last
|
|
packet containig data from this first unit arrives into the system
|
|
target decoder. This works fine if the video/audio streams are of
|
|
*very perfectly constant* or the packet size are *very* small
|
|
(ideally: the size of one access unit, that would mean variable
|
|
packet length).
|
|
Anyway: this parameter allows you to say that the System Target
|
|
Decoder should start decoding the first access unit after he
|
|
gets (startup_packet_delay + size_of_first_access_units[av])
|
|
packets of data.
|
|
This guarantees that the buffers are conveniently filled up.
|
|
Note that both the video stream offset and audio stream offset (ms)
|
|
add up even more bytes to this startup delay, but you can
|
|
tell conveniently that audio should start so many ms after video,
|
|
for example.
|
|
|
|
Sorry for no further doc, enjoy multiplexing A/V :)
|
|
|
|
Christoph.
|
|
|
|
moar@heaven.zfe.siemens.de
|
|
+---------------------------------------+--------------------------------+
|
|
| http://www.informatik.tu-muenchen.de/ | Christoph Moar |
|
|
| cgi-bin/nph-gateway/hphalle6/~moar/ | Kaulbachstr.29a |
|
|
| index.html | 80539 Munich |
|
|
| email:moar@informatik.tu-muenchen.de | voice: ++49 - 89 - 23862874 |
|
|
+---------------------------------------+--------------------------------+
|
|
|