[Libav-user] Muxing to file with unknown frame rate

[Carl Eugen Hoyos]

2017-04-12 16:29 GMT+02:00 Robert Jamieson <bob_jam11 at hotmail.com>:

> I am attempting to mux footage from a variety of webcams into standards
> based files. The footage is spread over a large number of files (all from
> the same camera). The files are a proprietary format containing the encoded
> frames that came directly from the camera (in most cases it is H.264, MJPEG
> or MPEG4 with G.711 or PCM16 audio). Audio is optional.
>
>
> I have created a pipeline for processing the footage that comprises of a
> reader for the files (this reads the frames and pushes them through the
> pipeline), a file sync that picks a suitable file format (based on the
> incoming video and audio formats) and writes the already encoded frames into
> the file. I am purposely not using a transcoder to save processing time.

Just curious:
Why can't you use the FFmpeg executable?

Or to say it differently: Is there an input sample file that is not
supported by FFmpeg?

> This is working well with one exception, I can't tell what the frame rate is
> ahead of time because I can't read the files before I process them.

FFmpeg's mov muxer only supports cfr, so you have to know the
framerate in advance.

Carl Eugen