[FFmpeg-user] Audio slowly getting out of sync

[Toerless Eckert]

How about just taking the same CLI and just change the output from HLS
to a single linear file to isolate the root cause. If Carl's theory of the
pipe being the culprit is right, then one would hope the problem also
shows with non-HLS output. Maybe kill stop/cont the pipe receiver process some times
to create the same delays that opening/closing HLS file segments might cause.

On Tue, Nov 22, 2016 at 08:50:34AM -0700, Roger Pack wrote:
> On 11/21/16, Gabor Alsecz <alseczg at gmail.com> wrote:
> > Dear All,
> >
> > I have an issue when encoding HLS stream from an RTSP mjpeg video stream +
> > USB audio via dshow.
> > At the beginning audio & video are in sync but slowly but steadily the
> > sound drifting out of sync. Video seems faster, approximately each 10
> > minutes the audio late +1 second.
> 
> I wonder if the RTSP has timestamps that are "getting out of sync"
> if you want to see if the show stuff is getting out of sync, run with
> "-loglevel debug" and it spits out tons of timing info.
> 
> Anyway there are some "vsync" options see if either help.
> 
> > I am using the following command:
> > ffmpeg -y -loglevel info -f dshow -i audio="Microphone (Trust Gaming
> > Microphone)" -pix_fmt bgr24 -video_size 1280x720 -framerate 25 -f rawvideo
> >   -i "-" -b:a 160k -ar 44100 -pix_fmt yuv420p -profile:v baseline -r 25 -g
> > 50 -hls_time 5 -hls_list_size 0 -hls_segment_filename file%03d.ts -f hls
> > out.m3u8
> >
> >
> > As you can see, this is rawvideo, feeding by memory bitmap "images" via
> > piping (from C#) + capture raw audio via dshow.
> >
> > Any idea what/how to solve this issue? Thanks!
> >
> >
> > br,
> > Gabor
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