[FFmpeg-cvslog] avformat/flacdec: support fast-seek
Ching Yi, Chan
git at videolan.org
Sun Oct 4 13:34:31 CEST 2015
ffmpeg | branch: master | Ching Yi, Chan <chingyichan.tw at gmail.com> | Thu Sep 24 13:04:40 2015 +0800| [5d926d5473886a20fed72e3e94e0637edf2d755a] | committer: Michael Niedermayer
avformat/flacdec: support fast-seek
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5d926d5473886a20fed72e3e94e0637edf2d755a
---
libavformat/flacdec.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 59 insertions(+), 1 deletion(-)
diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
index 4c1f943..4c7ee59 100644
--- a/libavformat/flacdec.c
+++ b/libavformat/flacdec.c
@@ -28,11 +28,27 @@
#include "vorbiscomment.h"
#include "replaygain.h"
+#define SEEKPOINT_SIZE 18
+
+typedef struct FLACDecContext {
+ int found_seektable;
+} FLACDecContext;
+
+static void reset_index_position(int64_t metadata_head_size, AVStream *st)
+{
+ /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */
+ int i;
+ for(i=0; i<st->nb_index_entries; i++) {
+ st->index_entries[i].pos += metadata_head_size;
+ }
+}
+
static int flac_read_header(AVFormatContext *s)
{
int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
uint8_t header[4];
uint8_t *buffer=NULL;
+ FLACDecContext *flac = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
@@ -58,6 +74,7 @@ static int flac_read_header(AVFormatContext *s)
case FLAC_METADATA_TYPE_CUESHEET:
case FLAC_METADATA_TYPE_PICTURE:
case FLAC_METADATA_TYPE_VORBIS_COMMENT:
+ case FLAC_METADATA_TYPE_SEEKTABLE:
buffer = av_mallocz(metadata_size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!buffer) {
return AVERROR(ENOMEM);
@@ -132,7 +149,23 @@ static int flac_read_header(AVFormatContext *s)
av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
return ret;
}
- } else {
+ } else if (metadata_type == FLAC_METADATA_TYPE_SEEKTABLE) {
+ const uint8_t *seekpoint = buffer;
+ int i, seek_point_count = metadata_size/SEEKPOINT_SIZE;
+ flac->found_seektable = 1;
+ if ((s->flags&AVFMT_FLAG_FAST_SEEK)) {
+ for(i=0; i<seek_point_count; i++) {
+ int64_t timestamp = bytestream_get_be64(&seekpoint);
+ int64_t pos = bytestream_get_be64(&seekpoint);
+ /* skip number of samples */
+ bytestream_get_be16(&seekpoint);
+ av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);
+ }
+ }
+ av_freep(&buffer);
+ }
+ else {
+
/* STREAMINFO must be the first block */
if (!found_streaminfo) {
RETURN_ERROR(AVERROR_INVALIDDATA);
@@ -169,6 +202,7 @@ static int flac_read_header(AVFormatContext *s)
if (ret < 0)
return ret;
+ reset_index_position(avio_tell(s->pb), st);
return 0;
fail:
@@ -249,14 +283,38 @@ static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_inde
return pts;
}
+static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
+ int index;
+ int64_t pos;
+ AVIndexEntry e;
+ FLACDecContext *flac = s->priv_data;
+
+ if (!flac->found_seektable || !(s->flags&AVFMT_FLAG_FAST_SEEK)) {
+ return -1;
+ }
+
+ index = av_index_search_timestamp(s->streams[0], timestamp, flags);
+ if(index<0 || index >= s->streams[0]->nb_index_entries)
+ return -1;
+
+ e = s->streams[0]->index_entries[index];
+ pos = avio_seek(s->pb, e.pos, SEEK_SET);
+ if (pos >= 0) {
+ return 0;
+ }
+ return -1;
+}
+
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_seek = flac_seek,
.read_timestamp = flac_read_timestamp,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "flac",
.raw_codec_id = AV_CODEC_ID_FLAC,
+ .priv_data_size = sizeof(FLACDecContext),
};
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