#253 extraction of avc out of different fileformats
i tried the following cmdl for demuxing avc video streams
from various file formats, with latest cvs code:
ffmpeg -y -i input.xxx -vcodec copy -f rawvideo -an
raw.264
my findings are:
1) avc-in-mp4
- streams created with nero recode2 cant be demuxed,
as there always is a crash in ffmpeg.exe right when
ffmpeg wants to begin the demuxing
- streams muxed with mp4creator can be demuxed, but
the output doesnt seem to be a valid raw avc stream
(filesize seems matching, but eg all the NAL info is lost).
i tried this with streams encoded with either x264 and
nero
- the same as for mp4creator muxed files, goes for .mp4
files muxed with videolan (NAL info lost)
all files can be demuxed correctly with vlc and
mp4creator
2) avc-in-mpgts
- trying to demux streams encoded with the moonlight
avc encoder results into a bunch of "error, pts < dts"
message (in my sample only two times: "frame= 1592
q=0.0 size= 5768kB time=63.6 bitrate=
742.9kbits/s", "frame= 3025 q=0.0 Lsize= 10473kB
time=120.9 bitrate= 709.5kbits/s" plus "muxing
overhead -19.573344%")
the resulting file includes NAL info (a not correct one
tough), but doesnt seem to be a valid raw stream
mplayer and vlc can demux the file correctly
3) avc-in-mpgps
- trying to demux a PS created with mainconcept results
into "could not find codec parameters"
it can be demuxed fine with mplayer and vlc correctly
for completeness:
4) avc-in-avi
- streams created with x264, mpegable, vss all can be
extracted to raw correctly (NAL is here, etc...)
btw it might be useful to describe the "-f" switch as
something like "force _output_ format" (cause it could
also refer to forcing ffmpeg to treat an input as a
specific format)
This Sourceforge bug tracker here has been abandoned many years ago.
Our new tracker can be found through http://www.ffmpeg.org/bugreports.html