[FFmpeg-user] ffmpeg with x264 codec - Aspect ratio doesn't follow input

chronek chronek at interia.eu
Wed May 25 14:53:09 CEST 2016


Didnt read to end before, are you have 2 aspect ratio in stream? Then 
you need split and process each part alone...

W dniu 2016-05-25 o 11:18, Richard F pisze:
> Thanks for your reply,
>
> The stream info for this file is as follows. As you can see the DAR
> starts as 16:9, but the aspect changes several times during the
> recording, x264 doesn't follow the changes, stays at 16:9.
>
> If I force the SAR as you suggest the output is narrower than 4:3 and
> still doesn't change with incoming aspect changes.
>
> Input #0, mpegts, from '00001.ts':
>    Duration: 00:59:49.47, start: 4529.649200, bitrate: 1477 kb/s
>    Program 132
>      Stream #0:0[0x18a1]: Video: mpeg2video (Main) ([2][0][0][0] /
> 0x0002), yuv420p(tv), 544x576 [SAR 32:17 DAR 16:9], max. 15000 kb/s, 25
> fps, 25 tbr, 90k tbn, 50 tbc
>      Stream #0:1[0x18a2](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
> Hz, stereo, s16p, 128 kb/s
>      Stream #0:2[0x18a3](eng): Audio: mp3 ([3][0][0][0] / 0x0003), 0
> channels, s16p
>      Stream #0:3[0x18a6](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
>
> If I analyse the stream 5 minutes into the programme, like so:
> ffmpeg -loglevel quiet -ss 00:05:00 -i "00001.ts" -t 10 -c copy
> -avoid_negative_ts 1 -f nut pipe:1 | ffmpeg -hide_banner -i pipe:0
>
> Then the video stream is as follows:
>
> Stream #0:0: Video: mpeg2video (Main) (mpg2 / 0x3267706D), yuv420p(tv),
> 544x576 [SAR 24:17 DAR 4:3], max. 15000 kb/s, SAR 32:17 DAR 16:9, 25
> fps, 25 tbr, 90k tbn, 50 tbc
>
> So it is meant to show as 4:3 here.
> I'm assuming the 2 sets of SAR/DAR are for container and stream which is
> why it still shows as 16:9 after ffmpeg processing ?
>
>
>
> On 25/05/2016 08:10, chronek wrote:
>> Maybe your source not have sar 1:1... setdar will not change
>> resolution, it will change only information about aspectratio and some
>> players not read desired aspect ratio... Best try change to resolution
>> what yuou want and setsar for it... ( -vf scale=x:y,setsar=1 )
>>
>> W dniu 2016-05-25 o 09:00, Richard F pisze:
>>> Hi list,
>>>
>>> I have a number of MPEG2 TS DVB recordings that have aspect ratio
>>> changes - e.g. older films or 4:3 programmes that have 16:9
>>> continuity, trailers, adverts etc.
>>>
>>> I want to transcode to H264 using ffmpeg (3.02), but the output
>>> aspect ratio does not follow the source when using the H264 codec.
>>> But the aspect ratio does follow when using the xvid/mp4 codec.
>>> I need x264 not mp4.
>>> The problem is that (I think) the container DAR or SAR stays at 16:9
>>> all the way through but the stream SAR or DAR doesn't follow the
>>> source for whatever reason
>>>
>>> Is there a way to make x264 output follow the source aspect ratio at
>>> the stream level ?
>>>
>>> Failing example :
>>> ffmpeg -y -i 00001.ts -map 0:0 -map 0:1 -map 0:3 -c:v libx264 -preset
>>> veryfast -profile:v high -level 4.0 -crf 20 -flags +loop -flags +ilme
>>> -vf yadif=0:-1:0 -c:a:0 aac -b:a:0 128k -c:s copy -f mpegts file-1.ts
>>> (same if I take out the profile and deinterlace settings)
>>>
>>> Working example (but large file and not so good quality, even if I
>>> could use it):
>>> ffmpeg -y -i 00001.ts -map 0:0 -map 0:1 -map 0:3 -c:v libxvid -q:v 3
>>> -c:a:0 aac -b:a:0 128k -c:s copy -f mpegts file-1.ts
>>>
>>> If I add -vf setdar=dar=4/3, I can force the x264 version to be 4/3
>>> but then all parts of the recording are always 4/3 which is also wrong.
>>>
>>> Behaviour is the same on VLC player, ffplay, and Kodi.
>>>
>>> Appreciate any pointers
>>> Thanks
>>> Richard
>>>
>>>
>>>
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