ffmpeg | branch: master | popcornmix <popcorn...@gmail.com> | Fri Jan 29 20:27:00 2016 +0000| [def56677e58de9aaa516a738b6469747662ac372] | committer: Michael Niedermayer
wtv: Speed up wtv index creation The index creation is O(N^2) with number of entries (typically thousands). On a Pi this can take more than 60 seconds to execute for a recording of a few hours. By replacing with an O(N) loop, this takes virtually zero time Liked-by: Paul B Mahol <one...@gmail.com> Reviewed-by: Peter Ross <pr...@xvid.org> Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=def56677e58de9aaa516a738b6469747662ac372 --- libavformat/wtvdec.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c index e8f6196..1deb4d9 100644 --- a/libavformat/wtvdec.c +++ b/libavformat/wtvdec.c @@ -1028,21 +1028,23 @@ static int read_header(AVFormatContext *s) pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16); if (pb) { int i; + AVIndexEntry *e = wtv->index_entries; + AVIndexEntry *e_end = wtv->index_entries + wtv->nb_index_entries - 1; + uint64_t last_position = 0; while (1) { uint64_t frame_nb = avio_rl64(pb); uint64_t position = avio_rl64(pb); + while (frame_nb > e->size && e <= e_end) { + e->pos = last_position; + e++; + } if (avio_feof(pb)) break; - for (i = wtv->nb_index_entries - 1; i >= 0; i--) { - AVIndexEntry *e = wtv->index_entries + i; - if (frame_nb > e->size) - break; - if (position > e->pos) - e->pos = position; - } + last_position = position; } + e_end->pos = last_position; wtvfile_close(pb); - st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp; + st->duration = e_end->timestamp; } } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
