From 3a6ccf4f3e3fc08e0dbb9079562cb3e01d19c662 Mon Sep 17 00:00:00 2001 From: Baptiste Coudurier Date: Fri, 29 Sep 2006 14:28:55 +0000 Subject: [PATCH] rudimentary binary seek Originally committed as revision 6382 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/mxf.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/libavformat/mxf.c b/libavformat/mxf.c index 28949ff38e..2d673916ca 100644 --- a/libavformat/mxf.c +++ b/libavformat/mxf.c @@ -976,6 +976,35 @@ static int mxf_probe(AVProbeData *p) { return 0; } +/* rudimentary binary seek */ +/* XXX: use MXF Index */ +static int mxf_read_seek(AVFormatContext *s, int stream_index, int64_t sample_time, int flags) +{ + AVStream *st = s->streams[stream_index]; + offset_t pos = url_ftell(&s->pb); + int64_t seconds; + int i; + + if (!s->bit_rate || sample_time < 0) + return -1; + seconds = av_rescale(sample_time, st->time_base.num, st->time_base.den); + url_fseek(&s->pb, (s->bit_rate * seconds) >> 3, SEEK_SET); + /* sync on KLV essence element */ + for (i = 0; i < 12 && url_ftell(&s->pb) < s->file_size; i++) { + int b = get_byte(&s->pb); + if (b == mxf_essence_element_key[0]) + i = 0; + else if (b != mxf_essence_element_key[i]) + i = -1; + } + if (i == 12) { /* found KLV key */ + url_fseek(&s->pb, -12, SEEK_CUR); + av_update_cur_dts(s, st, sample_time); + return 0; + } + url_fseek(&s->pb, pos, SEEK_SET); + return -1; +} AVInputFormat mxf_demuxer = { "mxf", @@ -985,5 +1014,5 @@ AVInputFormat mxf_demuxer = { mxf_read_header, mxf_read_packet, mxf_read_close, - NULL, + mxf_read_seek, }; -- 2.11.0