[FFmpeg-user] -movflags faststart revisited

[Reuben Martin]

On Sunday, February 26, 2017 5:44:56 PM CST JD wrote:
> On Sun, Feb 26, 2017 at 4:07 PM, Cley Faye <cleyfaye at gmail.com> wrote:
> > 2017-02-26 23:32 GMT+01:00 JD <jd1008 at gmail.com>:
> > > Are there any flags that will let me playback an unfinished transcode?
> > > Reason I am asking is that if my various options in the transcode
> > > command
> > > did not yield what I like, then I would like to abort the transcode.
> > 
> > ​mp4 files will never be playable without "finishing" them. But you can
> > interrupt the process at anytime with 'q'; that will properly close the
> > file so you can play it.​
> 
> ​Thanks - that is somewhat a panacea, especially if one
> is not 50% or more into the transcoding - so that issuing
> a 'q' will not lose too much is only say the transcoding is
> into 10 minutes of the video.
> 
> Now how about ffplay? I mean is/are there options
> to ffplay that would allow the playing of the unfinsihed
> mp4 file (without quitting the trancoding)?
> ​

Set the output format to flv. You can play flv before it’s finished encoding. 
If you decide you want to keep it, you can dump the video and audio streams 
from the flv into an mp4 file. (generally only takes a few seconds).

-Reuben