[FFmpeg-devel] 4:2:0 DV25 file wrongly identified as 4:1:1

[Niobos]

On 2010-09-22 12:46, Maksym Veremeyenko wrote:
> Niobos ???????(??):
> [...]
>>> If it helps, here's a some 4:1:1 DV from the Internet Archive:
>>> http://www.archive.org/download/TripTheLightPromo2/DanceTest2.mov
>>> ('dvc ')
>>> http://www.archive.org/download/ThroughtTheFirstBoca/ThroughFirstBoca.avi
>>> ('dvsd', DVCPRO)
>>> http://www.archive.org/download/Timothy_Leary_Archives_237_.dv/237_.dv (DVCPRO)
>>>
>>
>> I ran this ffmpeg command on all three:
>> ffmpeg -i "$f" -vcodec libx264 -vpre hq -b 1000k -acodec copy "$f.mkv"
>>
>> ffmpeg tells me the streams are "yuv411p", and from what I can tell
>> visually, they are correctly transcoded (and thus detected). I.e.
>> they're not scrambled as would have happened if they would be wrongly
>> detected as 4:2:0.
> 
> File *ThroughFirstBoca.avi* as you mention has fourcc 'dvsd' that is for
> PAL 4:2:0 dv content...

Input #0, avi, from 'ThroughFirstBoca.avi':
  Duration: 00:01:11.77, start: 0.000000, bitrate: 30202 kb/s
    Stream #0.0: Video: dvvideo, yuv411p, 720x480, 29.97 tbr, 29.97 tbn,
29.97 tbc
    Stream #0.1: Audio: pcm_s16le, 44100 Hz, 2 channels, s16, 1411 kb/s

According to the ffmpeg output, it's 4:1:1, and has the NTSC linecount
and NTSC framerate.
Also decoding this stream assuming these are correct yields a
normal-looking output.

Are you sure it's 4:2:0 PAL content?

Niobos