[FFmpeg-user] Trouble encoding h.264

Langdon langdon at gmail.com
Thu Mar 22 14:21:20 CET 2012


> 2012/3/22 Langdon <langdon at gmail.com>:
> > When I try to re-encode the two parts as h.264, the sound plays OK, but the
> > video is mostly gray in Media Player Classic Home Cinema, as well as when
> > uploaded to YouTube.  ffplay.exe seems to play it OK, but I'm creating the
> > video for mass consumption.
> >
> > ffmpeg -f u16le -acodec pcm_s16le -ac 2 -ar 48000 -i
> > c:/alka-video/workspace/06A.cat.a -i c:/alka-video/workspace/06A.cat.v
> > -vcodec libx264 -same_quant -y c:\alka-video/output/06A.avi > _h264.txt
>
> Try dropping -same_quant option, add -b:v (video bitrate here), or
> other options for quality setting.

I tried various -b:v values (1000k, 10000k, and 81000k), and while all
still mostly gray, some showed different variations of artifacts

I then ran ffprobe on the source video to see what I could glean from it...

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'source/06A.mov':
  Metadata:
    creation_time   : 2012-03-20 13:18:46
  Duration: 00:00:02.25, start: 0.000000, bitrate: 84045 kb/s
    Stream #0:0(eng): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz,
2 channels, s16, 1536 kb/s
    Metadata:
      creation_time   : 2012-03-20 13:18:47
      handler_name    : ?Apple Alias Data Handler
    Stream #0:1(eng): Video: prores (apch / 0x68637061), yuv422p10le,
1280x720, 81541 kb/s, 23.98 fps, 23.98 tbr, 23976 tbn, 23976 tbc
    Metadata:
      creation_time   : 2012-03-20 13:18:47
      handler_name    : ?Apple Alias Data Handler
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74)
    Metadata:
      creation_time   : 2012-03-20 13:18:49
      handler_name    : ?Apple Alias Data Handler
      timecode        : 01:00:32:21
Unsupported codec with id 0 for input stream 2

So I tried -b:v 81541k, to no avail.

Interestingly enough, the source video converts to h.264 just fine
(from ProRes), but I can't concatenate ProRes. =[

I don't see anything in -help to specify tbn or tbc (the only 2 values
that different from input to output at this point).


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