ffmpeg | branch: master | Tomas Härdin <g...@haerdin.se> | Sat Sep 14 11:48:09 2024 +0200| [e3fa469a55a09901d59c37e6977e0154a1c0ce47] | committer: Tomas Härdin
lavf/mxfdec: Speed up klv_read_packet() > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e3fa469a55a09901d59c37e6977e0154a1c0ce47 --- libavformat/mxfdec.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index 24f4ed1c33..99bf352e00 100644 --- a/libavformat/mxfdec.c +++ b/libavformat/mxfdec.c @@ -458,10 +458,26 @@ static int mxf_read_sync(AVIOContext *pb, const uint8_t *key, unsigned size) return i == size; } +// special case of mxf_read_sync for mxf_klv_key +static int mxf_read_sync_klv(AVIOContext *pb) +{ + uint32_t key = avio_rb32(pb); + // key will never match mxf_klv_key on EOF + if (key == AV_RB32(mxf_klv_key)) + return 1; + + while (!avio_feof(pb)) { + key = (key << 8) | avio_r8(pb); + if (key == AV_RB32(mxf_klv_key)) + return 1; + } + return 0; +} + static int klv_read_packet(MXFContext *mxf, KLVPacket *klv, AVIOContext *pb) { int64_t length, pos; - if (!mxf_read_sync(pb, mxf_klv_key, 4)) + if (!mxf_read_sync_klv(pb)) return AVERROR_INVALIDDATA; klv->offset = avio_tell(pb) - 4; if (klv->offset < mxf->run_in) @@ -3982,6 +3998,7 @@ static int mxf_read_packet(AVFormatContext *s, AVPacket *pkt) ret = klv_read_packet(mxf, &klv, s->pb); if (ret < 0) break; + // klv.key[0..3] == mxf_klv_key from here forward max_data_size = klv.length; pos = klv.next_klv - klv.length; PRINT_KEY(s, "read packet", klv.key); _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
