[FFmpeg-user] overlay_qsv with hardware decode and encode

[BloodMan]

Hi Vlad,

W dniu 2025-03-01 o 08:35, Vladimir Mishonov via ffmpeg-user pisze:
> On 2025-03-01 00:36, Vladimir Mishonov via ffmpeg-user wrote:
>> On 2025-02-28 23:26, BloodMan wrote:
>>> Hi Vladimir,
>>>
>>> I see on previous posts that resolutions are different, but also 
>>> frame rates are different and colour spaces (bt709 vs "") are different.
>>>
>>> Are you really sure the problem is the resolution?
>>> (I have no way to check, I'm just thinking out)
>>
>> It is possible, but needs furher testing to say for sure.
> 
> BloodMan, it turns out you were right!
> 
> I've just tested with a spare RTSP IP camera that provides both a 
> primary and a backup stream. Both streams have the same characteristics 
> EXCEPT the resolution, of course.
> 
> And this command works:
> 
> ffmpeg -loglevel verbose \
>   -hwaccel vaapi -hwaccel_output_format vaapi -rtsp_transport tcp -i 
> rtsp://login:password@test.ip.camera/primary/stream \
>   -hwaccel vaapi -hwaccel_output_format vaapi -rtsp_transport tcp -i 
> rtsp://login:password@test.ip.camera/backup/stream \
>   -filter_complex "[0:v][1:v]overlay_vaapi=w=500" \
>   -c:v h264_vaapi -global_quality 25 -g 50 -r 25 -an test.mkv
> 
> The produced video file contains the expected output.
> 
> Of course I still need to figure out how to work around the case when 
> the streams are from different sources and their properties might not 
> match. If that is at all possible, of course.
> [...]

I suspect colorspace, so try explicitly set on input (or convert) 
colorspace maybe... There is a lot of options -vf, -pix_fmt, -sws_flags 
etc. you can test - find them on ffmpeg wiki here
https://trac.ffmpeg.org/wiki/colorspace

Have fun :)

-- 
BloodMan