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

[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.

Gyan