[FFmpeg-devel] [PATCH] Clip-Wrapped MXF support (attempt #4)
Tue Jan 25 20:44:50 CET 2011
On Tue, Jan 25, 2011 at 01:38:10PM +0200, Maksym Veremeyenko wrote:
> @@ -524,13 +530,35 @@ static int mxf_read_source_package(void *arg, ByteIOContext *pb, int tag, int si
> static int mxf_read_index_table_segment(void *arg, ByteIOContext *pb, int tag, int size, UID uid)
> + MXFIndexTableSegment *segment = (MXFIndexTableSegment *)arg;
> + /* check small EditUnitByteCount for audio */
> + if (!mxf->current_klv_bsize)
> + mxf->current_klv_bsize = 1024;
IMO this "default" is a lot too small, one packet per 1 kB is a
massive overhead if you end up using it for e.g. a 100 MBit/s
MPEG-2 just because it does not have any such metadata setting.
1 kB sized packets means > 2% memory overhead in general and
for above example it would be about 12000 demuxer calls per second!
Apart from that I retract my earlier objections, I wasn't aware
the whole file would be read into memory currently.
More information about the ffmpeg-devel