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avformat/flacdec: support fast-seek 

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Ching Yi, Chan 2015-09-24 13:04:40 +08:00 committed by Michael Niedermayer
parent 513fcd4167
commit 5d926d5473
1 changed files with 59 additions and 1 deletions
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60
libavformat/flacdec.c
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@ -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),
};