[Ffmpeg-devel] [PATCH] ODML AVI Duration

[Michael Niedermayer]

Hi

On Tue, Aug 22, 2006 at 07:18:16PM -0500, Brian Brice wrote:
> Michael Niedermayer wrote:
> >Hi
> >
> >On Tue, Aug 22, 2006 at 04:38:39PM -0500, Brian Brice wrote:
> >>Michael Niedermayer wrote:
> >>>Hi
> >>>
> >>>On Tue, Aug 22, 2006 at 03:21:23PM -0500, Brian Brice wrote:
> >>>>If I encoded an AVI that was over 2 GB (or 4m:43s DV), then video
> >>>>players would read the wrong duration, thus not being able to show the
> >>>>entire clip.  For example, encoding a DV clip that is about 5 minutes
> >>>>in duration:
> >>>>
> >>>>ffmpeg -i INPUT.mpg -f avi -vcodec dvvideo -acodec pcm_s16le -s ntsc
> >>>>-r ntsc -ar 48000 -pix_fmt yuv411p -t 00:05:00 OUTPUT.avi
> >>>>
> >>>>Windows Media Player and even ffmpeg would report the duration as 4:43.
> >>>>This patch is to write the proper lengths in the AVI and stream headers.
> >>>>If the file contains only 1 RIFF, then all will be the same.  If there
> >>>>is more than 1 RIFF, then in the write_trailer, it updates the odml's
> >>>>length along with the headers.
> >>>quoting the odml spec
> >>>"The dwTotalFrames field indicates the size (number of frames) within 
> >>>the first RIFF
> >>>chunk."
> >>>
> >>>...
> >>>
> >>>"Extended AVI Header (dmlh)
> >>>typedef struct {
> >>>  DWORD dwTotalFrames;
> >>>} ODMLExtendedAVIHeader;
> >>>Total Frames
> >>>The dwTotalFrames field indicates the real size of the AVI file. Since 
> >>>the same field in the
> >>>Main AVI Header indicates the size within the first RIFF chunk.
> >>>"
> >>OK.  This version updates ONLY the stream headers' length but leaves
> >>the avih's total frames referring to ONLY the first RIFF's.  Having ONLY
> >>the streams' headers updated reports the correct duration in both
> >>Windows Media Player and ffmpeg.
[...]
> >and it contains tabs and consequently messed up indention
> 
> Added.  Forgot to turn off tabs.. :-(
[...]
> +        if(au_ssize == 0) {
> +           put_le32(pb, avi->packet_count[n]);
> +        } else {
> +           put_le32(pb, avi->audio_strm_length[n] / au_ssize);
> +        }
> +        if(stream->codec_type == CODEC_TYPE_VIDEO)
> +           nb_frames = FFMAX(nb_frames, avi->packet_count[n]);

these also arent indented correctly (they have 3 spaces instead of 4)

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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