[Ffmpeg-devel] [PATCH] ODML AVI Duration

[Brian Brice]

Michael Niedermayer wrote:
> 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)
> 
OK.  Corrected.

-- 
Brian Brice
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