From 795d9594cfaf9b6c9ce0c60f86c6e51636096a5a Mon Sep 17 00:00:00 2001 From: "Panagiotis H.M. Issaris" Date: Tue, 15 Nov 2011 18:35:03 +0100 Subject: [PATCH] applehttp: Fix seeking in streams not starting at DTS=0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Apple HTTP Live Streaming demuxer's implementation of seeking searches for the MPEG TS segment which contains the requested timestamp. In its current implementation it assumes that the first segment will start from 0. But, MPEG TS streams do not necessarily start with timestamp (near) 0, causing seeking to fail for those streams. This also occurs when using live streaming of HTTP Live Streams. In this case sliding playlists may be used, which means that in that case only the last x encoded segments are stored, the earlier segments get deleted from disk and removed from the playlist. Because of this, when starting playback of a stream in the middle of such a broadcast, the initial segment fetched after parsing the m3u8 playlist will not start from timestamp (near) 0, causing (the admittedly limited live) seeking to fail. This patch changes this demuxers seeking implementation to use the initial DTS as an offset for searching the segments containing the requested timestamp. Signed-off-by: Martin Storsjö --- libavformat/applehttp.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/libavformat/applehttp.c b/libavformat/applehttp.c index e0773ae87f..366d8327ff 100644 --- a/libavformat/applehttp.c +++ b/libavformat/applehttp.c @@ -99,6 +99,7 @@ typedef struct AppleHTTPContext { int cur_seq_no; int end_of_segment; int first_packet; + int64_t first_timestamp; AVIOInterruptCB *interrupt_callback; } AppleHTTPContext; @@ -527,6 +528,7 @@ static int applehttp_read_header(AVFormatContext *s, AVFormatParameters *ap) } c->first_packet = 1; + c->first_timestamp = AV_NOPTS_VALUE; return 0; fail: @@ -591,6 +593,9 @@ start: if (!var->pb.eof_reached) return ret; reset_packet(&var->pkt); + } else { + if (c->first_timestamp == AV_NOPTS_VALUE) + c->first_timestamp = var->pkt.dts; } } /* Check if this stream has the packet with the lowest dts */ @@ -639,7 +644,10 @@ static int applehttp_read_seek(AVFormatContext *s, int stream_index, for (i = 0; i < c->n_variants; i++) { /* Reset reading */ struct variant *var = c->variants[i]; - int64_t pos = 0; + int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ? 0 : + av_rescale_rnd(c->first_timestamp, 1, + stream_index >= 0 ? s->streams[stream_index]->time_base.den : AV_TIME_BASE, + flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP); if (var->input) { ffurl_close(var->input); var->input = NULL;