[FFmpeg-devel] [RFC] use ff_avc_find_startcode in ff_find_start_code
Tue Feb 19 16:17:03 CET 2008
On Tue, Feb 19, 2008 at 03:06:37PM -0000, M?ns Rullg?rd wrote:
> Reimar D?ffinger wrote:
> > On Tue, Feb 19, 2008 at 03:28:27PM +0100, Reimar D?ffinger wrote:
> >> For decoding my THX_Science_FLT_1920.gxf, ff_find_start_code in
> >> mpeg_decode_frame
> >> is called 73754 times for 353 frames, the average amount of data skipped is
> >> 1272.626343 bytes.
> > And uh... yes, this does indeed mean that 90% of the file's data is
> > trash...
> > Probably there is not much point in concentrating on this kind of thing,
> > but I'd expect these kind of long skips might be common for DVDs in
> > order to try to get a more constant bitrate as well...
> DVDs generally use the standard MPEG2-PS padding stream, so this should
> not be an issue there.
I checked that btw., with DVDs there usually (more than 50% of cases) is
a 5 byte skip and then the start code.
But the Spaceballs DVD has an skip of 140 byte on average in the first
10 minutes, going down to an average of 70 later on.
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