[MPlayer-users] Dump raw compressed video -dumpvideo

[Bill Crockett]

mplayer -dumpvideo some_video.mpg

Dump raw compressed video stream to stream.dump

To see these raw videos, I would use something like this:

mplayer -demuxer rawvideo -rawvideo fps=23.976:w=1280:h=720 stream.dump

mplayer -demuxer rawvideo -rawvideo fps=23.976:w=1280:h=720:format=i420:size=1382400 stream.dump

This seems to work with mpeg videos and 1 or 2 other formats, but is not working with an mp4 video with the x264 codec. The video has nothing but static and will only play for about 4 seconds. Then this:

Frame too small! (84152<1382400) Wrong format?

What format and frame size is correct please?

[Carl Eugen Hoyos]

Post by Bill Crockett
mplayer -dumpvideo some_video.mpg
Dump raw compressed video stream to stream.dump
mplayer -demuxer rawvideo -rawvideo fps=23.976:w=1280:h=720 stream.dump
mplayer -demuxer rawvideo -rawvideo
fps=23.976:w=1280:h=720:format=i420:size=1382400 stream.dump

These command lines are not supposed to support "raw compressed
video" (but only raw uncompressed video), they should work with:
$ mplayer stream.dump

Post by Bill Crockett
This seems to work with mpeg videos and 1 or 2 other formats, but is not
working with an mp4 video with the x264 codec.

The needed extradata is missing when dumping the video stream from mp4
with -dumpvideo. You cannot easily fix this.
One alternative is to use ffmpeg for this use-case:
$ ffmpeg -i input.mp4 -vcodec copy dump.h264

Carl Eugen

[Bill Crockett]

From: "Carl Eugen Hoyos"
To: "MPlayer usage questions, feature requests, bug reports"
<mplayer-***@mplayerhq.hu>
Sent: Wednesday, March 14, 2018 1:48 AM
Subject: Re: [MPlayer-users] Dump raw compressed video -dumpvideo

2018-03-12 8:28 GMT+01:00, Bill Crockett

Post by Bill Crockett
mplayer -dumpvideo some_video.mpg
Dump raw compressed video stream to stream.dump
mplayer -demuxer rawvideo -rawvideo fps=23.976:w=1280:h=720 stream.dump
mplayer -demuxer rawvideo -rawvideo
fps=23.976:w=1280:h=720:format=i420:size=1382400 stream.dump

These command lines are not supposed to support "raw compressed
$ mplayer stream.dump

Post by Bill Crockett
This seems to work with mpeg videos and 1 or 2 other formats, but is not
working with an mp4 video with the x264 codec.

The needed extradata is missing when dumping the video stream from mp4
with -dumpvideo. You cannot easily fix this.
$ ffmpeg -i input.mp4 -vcodec copy dump.h264
Carl Eugen

Thanks for your info on this.

Unfortunately, the FFmpeg dump.h264 produced the same results as MPlayer. I
even tried ffplay -f rawvideo -pixel_format yuv420p -video_size
1280x720 -framerate 23.976 dump.h264. Nothing but static on the screen.

These command lines are not supposed to support "raw compressed
video" (but only raw uncompressed video)

I think you are right, and that the -dumpvideo command is ripping too much
of the header in mp4 or mov files encoded with x264 avc making it impossible
to play.

I have spent too much time on this and will move on.

[Carl Eugen Hoyos]

Post by Bill Crockett

Post by Carl Eugen Hoyos
$ ffmpeg -i input.mp4 -vcodec copy dump.h264

Unfortunately, the FFmpeg dump.h264 produced the same
results as MPlayer.

Always use current FFmpeg, not an old version (that needs a
bitstream filter).

Carl Eugen