quick question, have movie, cut , rendered sony vegas original format .wmv file. here comes tricky part, movie when played, either vlc or wmp, has resolution of 656x480 ... when run ffmpeg -i on it, says has resolution of 600x480 ....
i took time of capturing frame , croping photoshop , 656 , not 600 ffmpeg reporting, why happening? how fix headers resolution? have impact on video re-rendering? said, vlc , wmp seems not care incorrect headers , playing right, but, jwplayer seems using header information, don't blame him, correct that, why video headers wrong?
ffmpeg -i trailer.wmv input #0, asf, 'trailer.wmv': duration: 00:01:04.93, start: 3.000000, bitrate: 2144 kb/s stream #0.0: audio: wmav2, 44100 hz, mono, 32 kb/s stream #0.1: video: wmv3, yuv420p, 600x480 [par 59:54 dar 295:216], 2065 kb/ s, 25.00 tb(r)
and yeah, par/dar parameters wrong, honestly, don't understand technical shit, watch video , make sure good, feedback appreciated :p
is there way change container information ffmpeg applications use container information don't render video incorrectly?
ffmpeg 100% correct, technical stuff important :d
your par (pixel aspect ratio) , dar (display aspect ratio) correct, , proved capturing screenshot , measuring.
what threw off par. not pixels square! ie: 1:1, although downloaded videos never noticed. players such vlc recognize par value , stretch video accordingly meet dar. dvd video great example of this.
see also: http://en.wikipedia.org/wiki/pixel_aspect_ratio
so ffmpeg says video width 600. multiply par , you'll "real" width. meaning if pixels square , not rectangular (horizontally). 600 * (59/54) = 656 (rounded) number familiar?
now take "real" size: 656 / 480 = 1.366 , @ dar: 295 / 216 = 1.366
magic!
as found out not video players smart enough recognize par , perform appropriate stretching. can change 1:1 using ffmpeg using setsar , scale video filters.
ffmpeg ...stuff... -vf "scale=656:480,setsar=1:1" ...more stuff...
for curious, it's called setsar because it's refered sample (aka pixel) aspect ratio: http://ffmpeg.org/ffmpeg.html#setsar-1
hope help, i'm sure confuses many people (including myself) @ first.
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