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

[Richard F]

Yes - that's the exact issue - multiple aspect ratio changes, and I'm
not sure how to find where they occur without a lot of complexity
About 7 years ago Jarmo Torvinen proposed something to address this
exact issue - did this ever reach the build, if so how to activate ?
http://x264-devel.videolan.narkive.com/TlgcMaKZ/reconfiguring-x264-aspect-ratio-in-the-middle-of-stream


On 25/05/2016 13:53, chronek wrote:
> 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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