[FFmpeg-devel] H.264 SDP sprop-parameter-sets not being generated

brian mcgann brianm
Thu Aug 6 19:53:47 CEST 2009


Please excuse any naivete - I am new to this list but intensely interested.

I have successfully generated an H.264 MP4 (plays successfully with QT
Player) from an FLV via:

"ffmpeg -i Test.flv -vcodec copy -acodec copy Test.flv.mp4"

I am now trying to stream this MP4 by means of RTP with:

"ffmpeg -fflags +genpts -re -i Test.flv.mp4 -vcodec copy -an -f rtp rtp://
127.0.0.1:10000 -vn -acodec copy -f rtp rtp://127.0.0.1:20000 -newaudio"

from which the following is displayed:

FFmpeg version SVN-r19325, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --disable-shared --disable-mmx --enable-libmp3lame
--enable-libfaac --enable-libfaad --enable-libx264 --enable-gpl
--enable-nonfree --disable-optimizations --enable-debug --disable-stripping
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.32. 0 / 52.32. 0
  libavformat   52.36. 0 / 52.36. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on Aug  6 2009 06:45:24, gcc: 4.0.1 (Apple Inc. build 5490)

Seems stream 0 codec frame rate differs from container frame rate: 30.00
(30/1) -> 15.00 (15/1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Test.flv.mp4':
  Duration: 00:37:28.36, start: 0.000000, bitrate: 452 kb/s
    Stream #0.0(und): Video: h264, yuv420p, 512x288 [PAR 1:1 DAR 16:9], 15
tbr, 1k tbn, 30 tbc
    Stream #0.1(und): Audio: aac, 44100 Hz, 1 channels, s16
Output #0, rtp, to 'rtp://127.0.0.1:10000':
    Stream #0.0(und): Video: libx264, yuv420p, 512x288 [PAR 1:1 DAR 16:9],
q=2-31, 90k tbn, 1k tbc
Output #1, rtp, to 'rtp://127.0.0.1:20000':
    Stream #1.0(und): Audio: libfaac, 44100 Hz, 1 channels, s16
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #1.0

SDP:
v=0
o=- 0 0 IN IP4 127.0.0.1
t=0 0
s=No Name
a=tool:libavformat 52.36.0
m=video 10000 RTP/AVP 96
c=IN IP4 127.0.0.1
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1; sprop-parameter-sets=
m=audio 20000 RTP/AVP 96
c=IN IP4 127.0.0.1
a=rtpmap:96 MPEG4-GENERIC/44100/1
a=fmtp:96
profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;
config=1208

Clearly the "sprop-parameter-sets" entry is missing, and in stepping through

avc.c:ff_avc_find_startcode() called from sdp.c:extradata2psets(), the H.264
start code is not being found.

I would greatly appreciate any pointers.



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