[FFmpeg-user] Compressibility Check

[Brendan Brewster]

Hi,

I am trying to implement a compressibility check via ffmpeg to determine an
appropriate resolution for the full encode.

My script is currently determining the interval and length of snippets to
test with and then running a sequence of calls to ffmpeg to gather a total
size for the samples as follows:

$ ffmpeg -i VTS_01_PGC_01_1.VOB -ss 0 -t 9 -filter:v yadif -target ntsc-dvd
-f mpeg2video -mbd rd -trellis 1 -cmp 2 -subcmp 2 -g 15 - -an 2>/dev/null |
wc -c
$ ffmpeg -i VTS_01_PGC_01_1.VOB -ss 179 -t 9 -filter:v yadif -target
ntsc-dvd -f mpeg2video -mbd rd -trellis 1 -cmp 2 -subcmp 2 -g 15 - -an
2>/dev/null | wc -c
...
(and so on)

This works but the problem with this really stems from how long it takes to
seek and process subsequent segments of the input especially as we approach
the latter portion. Is there a better way encode multiple segments like
this, say, in one pass?

Any other ideas or feedback?

Thanks,
Brendan