[FFmpeg-cvslog] flac demuxer: improve seeking
Rainer Hochecker
git at videolan.org
Mon Apr 14 18:40:19 CEST 2014
ffmpeg | branch: master | Rainer Hochecker <fernetmenta at online.de> | Sat Apr 12 18:13:32 2014 +0200| [e1fcd3a007591193891df1095f5263e9e5e71958] | committer: Rainer Hochecker
flac demuxer: improve seeking
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e1fcd3a007591193891df1095f5263e9e5e71958
---
libavcodec/flac_parser.c | 13 +++++++++++++
libavformat/flacdec.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 58 insertions(+)
diff --git a/libavcodec/flac_parser.c b/libavcodec/flac_parser.c
index ba1f060..6ff4d9c 100644
--- a/libavcodec/flac_parser.c
+++ b/libavcodec/flac_parser.c
@@ -489,6 +489,14 @@ static int get_best_header(FLACParseContext* fpc, const uint8_t **poutbuf,
&fpc->wrap_buf,
&fpc->wrap_buf_allocated_size);
+
+ if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS){
+ if (header->fi.is_var_size)
+ fpc->pc->pts = header->fi.frame_or_sample_num;
+ else if (header->best_child)
+ fpc->pc->pts = header->fi.frame_or_sample_num * header->fi.blocksize;
+ }
+
fpc->best_header_valid = 0;
fpc->last_fi_valid = 1;
fpc->last_fi = header->fi;
@@ -516,6 +524,11 @@ static int flac_parse(AVCodecParserContext *s, AVCodecContext *avctx,
s->duration = fi.blocksize;
if (!avctx->sample_rate)
avctx->sample_rate = fi.samplerate;
+ if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS){
+ fpc->pc->pts = fi.frame_or_sample_num;
+ if (!fi.is_var_size)
+ fpc->pc->pts *= fi.blocksize;
+ }
}
*poutbuf = buf;
*poutbuf_size = buf_size;
diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
index bbbbf66..f640fec 100644
--- a/libavformat/flacdec.c
+++ b/libavformat/flacdec.c
@@ -162,12 +162,57 @@ static int flac_probe(AVProbeData *p)
return AVPROBE_SCORE_EXTENSION;
}
+static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index,
+ int64_t *ppos, int64_t pos_limit)
+{
+ AVPacket pkt, out_pkt;
+ AVStream *st = s->streams[stream_index];
+ int ret;
+
+ if (avio_seek(s->pb, *ppos, SEEK_SET) < 0)
+ return AV_NOPTS_VALUE;
+
+ av_init_packet(&pkt);
+ st->parser = av_parser_init(st->codec->codec_id);
+ if (!st->parser){
+ return AV_NOPTS_VALUE;
+ }
+ st->parser->flags |= PARSER_FLAG_USE_CODEC_TS;
+
+ for (;;){
+ ret = ff_raw_read_partial_packet(s, &pkt);
+ if (ret < 0){
+ if (ret == AVERROR(EAGAIN))
+ continue;
+ else
+ return AV_NOPTS_VALUE;
+ }
+ av_init_packet(&out_pkt);
+ ret = av_parser_parse2(st->parser, st->codec,
+ &out_pkt.data, &out_pkt.size, pkt.data, pkt.size,
+ pkt.pts, pkt.dts, *ppos);
+
+ if (out_pkt.size){
+ int size = out_pkt.size;
+ av_free_packet(&out_pkt);
+ if (st->parser->pts != AV_NOPTS_VALUE){
+ // seeking may not have started from beginning of a frame
+ // calculate frame start position from next frame backwards
+ *ppos = st->parser->next_frame_offset - size;
+ return st->parser->pts;
+ }
+ }
+ }
+ return AV_NOPTS_VALUE;
+}
+
AVInputFormat ff_flac_demuxer = {
.name = "flac",
.long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
.read_probe = flac_probe,
.read_header = flac_read_header,
.read_packet = ff_raw_read_partial_packet,
+ .read_timestamp = flac_read_timestamp,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "flac",
.raw_codec_id = AV_CODEC_ID_FLAC,
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