[FFmpeg-user] Sync. Issue. Video Gradually Falls Behind

[Carl Eugen Hoyos]

Am Mi., 27. Jan. 2021 um 19:09 Uhr schrieb Thomas Seilund via
ffmpeg-user <ffmpeg-user at ffmpeg.org>:
>
>
> On 1/26/21 6:01 PM, Carl Eugen Hoyos wrote:
> > Am Di., 26. Jan. 2021 um 16:51 Uhr schrieb Thomas Seilund via
> > ffmpeg-user <ffmpeg-user at ffmpeg.org>:
> >
> >> Input #0, h264, from 'pipe:':
> >>     Duration: N/A, bitrate: N/A
> >>       Stream #0:0: Video: h264 (High), yuv420p(progressive), 1280x720, 25
> >> fps, 25 tbr, 1200k tbn, 50 tbc
> >> Guessed Channel Layout for Input Stream #1.0 : stereo
> >> Input #1, pulse, from
> >> 'alsa_input.usb-046d_HD_Pro_Webcam_C920_9D715A9F-02.analog-stereo':
> >>     Duration: N/A, start: 1611673439.592751, bitrate: 1536 kb/s
> >>       Stream #1:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
> >> Guessed Channel Layout for Input Stream #2.0 : stereo
> >> Input #2, pulse, from
> >> 'alsa_output.platform-bcm2835_audio.analog-stereo.monitor':
> >>     Duration: N/A, start: 1611673439.612473, bitrate: 1536 kb/s
> >>       Stream #2:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
> > I don't think you can synchronize a stream with no start time with
> > two streams with start time, at least not without additional options.

> I assume you mean that the video stream does not have a start time and
> the two audio streams do.

Correct.

> Can I set the start time for the video stream to avoid video from
> falling more and more behind?

The setpts filter should allow you to set the audio start times to 0.

Carl Eugen