[FFmpeg-devel] [PATCH] qt-faststart: Add mode for probing faststart-ness

[Tomas Härdin]

lör 2018-07-28 klockan 10:31 +0530 skrev Gyan Doshi:
> 
> On 28-07-2018 03:33 AM, Tomas Härdin wrote:
> > 
> > woot! I didn't know the mov demuxer dumped such things. It is quite
> > slow however, since it will scan through every leaf atom in the
> > file.
> > For example, running time ffmpeg -i input.mov -v 56 2>&1 | wc on a
> > 1.5
> > GiB MP4 on an SSD takes:
> 
> Use the subfile protocol to forgo parsing the whole file, e.g.
> 
>      ffmpeg -i subfile,,start,0,end,10000,,:in.mp4 -v 56 2>&1 | grep
> -e 
> "type:'moov'" -e "type:'mdat'" | head -1 | grep moov
> 
> This assumes that at least one of the two targeted boxes moov/mdat
> start 
> within the first 10000 bytes.

Neat. This is similar to the first suggestion I had to the peertube
devs, dd:ing off the first MiB or so then probing that. We'll see what
they say, and what Baptiste thinks I guess

/Tomas