From e311363245db963389dd62e8028641fbcdac35b5 Mon Sep 17 00:00:00 2001 From: Kostya Shishkov Date: Thu, 28 Dec 2006 05:33:31 +0000 Subject: Enable forward seek in Musepack demuxer Originally committed as revision 7381 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/mpc.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) (limited to 'libavformat/mpc.c') diff --git a/libavformat/mpc.c b/libavformat/mpc.c index abc7617695..1c941d8159 100644 --- a/libavformat/mpc.c +++ b/libavformat/mpc.c @@ -71,6 +71,7 @@ static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap) c->curframe = 0; c->lastframe = -1; c->curbits = 8; + c->frames_noted = 0; st = av_new_stream(s, 0); if (!st) @@ -156,15 +157,42 @@ static int mpc_read_close(AVFormatContext *s) return 0; } +/** + * Seek to the given position + * If position is unknown but is within the limits of file + * then packets are skipped unless desired position is reached + * + * Also this function makes use of the fact that timestamp == frameno + */ static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { AVStream *st = s->streams[stream_index]; MPCContext *c = s->priv_data; + AVPacket pkt1, *pkt = &pkt1; + int ret; int index = av_index_search_timestamp(st, timestamp, flags); - if (index < 0) - return -1; - c->curframe = st->index_entries[index].pos; + uint32_t lastframe; + /* if found, seek there */ + if (index >= 0){ + c->curframe = st->index_entries[index].pos; + return 0; + } + /* if timestamp is out of bounds, return error */ + if(timestamp < 0 || timestamp >= c->fcount) + return -1; + /* seek to the furthest known position and read packets until + we reach desired position */ + lastframe = c->curframe; + if(c->frames_noted) c->curframe = c->frames_noted - 1; + while(c->curframe < timestamp){ + ret = av_read_frame(s, pkt); + if (ret < 0){ + c->curframe = lastframe; + return -1; + } + av_free_packet(pkt); + } return 0; } -- cgit v1.2.3