On Fri, Sep 25, 2015 at 09:22:41AM +0800, Ching-Yi Chan wrote: > I do it with AVFMT_FLAG_FAST_SEEK flag. > > > 2015-09-24 23:47 GMT+08:00 wm4 <nfx...@googlemail.com>: > > > On Thu, 24 Sep 2015 23:41:03 +0800 > > Ching-Yi Chan <chingyichan...@gmail.com> wrote: > > > > > Is it acceptable to provide an option for different methods > > > between accuracy seek and fast but inaccurate. > > > > > > For example, mp3dec having "usetoc" option to seek by toc. > > > > You could use the AVFMT_FLAG_FAST_SEEK flag. (It's a flag set on the > > format context.) > > _______________________________________________ > > ffmpeg-devel mailing list > > ffmpeg-devel@ffmpeg.org > > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > >
> flacdec.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 42 insertions(+), 1 deletion(-)
> 980c23fbd623f488c24194ec92d75aebe5e183f8
> 0001-avformat-flacdec-support-fast-seek.patch
> From 2e1d69e0a24455136d1a5dcc0898eac1bb2cb602 Mon Sep 17 00:00:00 2001
> From: "Ching Yi, Chan" <chingyichan...@gmail.com>
> Date: Thu, 24 Sep 2015 13:04:40 +0800
> Subject: [PATCH] avformat/flacdec: support fast-seek
>
> ---
> libavformat/flacdec.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 42 insertions(+), 1 deletions(-)
>
> diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
> index 4c1f943..3e4d867 100644
> --- a/libavformat/flacdec.c
> +++ b/libavformat/flacdec.c
> @@ -28,11 +28,14 @@
> #include "vorbiscomment.h"
> #include "replaygain.h"
>
> +#define SEEKPOINT_SIZE 18
> +
> 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;
> +
> AVStream *st = avformat_new_stream(s, NULL);
> if (!st)
> return AVERROR(ENOMEM);
> @@ -58,6 +61,7 @@ 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 +136,20 @@ 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;
> + 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 +186,12 @@ static int flac_read_header(AVFormatContext *s)
> if (ret < 0)
> return ret;
>
> + /* the real seek index offset should be the size of metadata blocks with
> the offset in the frame blocks */
> + int metadata_head_size = avio_tell(s->pb);
this should be int64_t probably
also declarations and statments should not be mixed
> + int i;
> + for(i=0; i<st->nb_index_entries; i++) {
> + st->index_entries[i].pos += metadata_head_size;
> + }
> return 0;
>
> fail:
> @@ -249,12 +272,30 @@ 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) {
> + if (!(s->flags&AVFMT_FLAG_FAST_SEEK)) {
> + return -1;
> + }
> +
> + int index = av_index_search_timestamp(s->streams[0], timestamp, flags);
> + if(index<0 || index >= s->streams[0]->nb_index_entries)
> + return -1;
> +
> + AVIndexEntry e = s->streams[0]->index_entries[index];
> + int ret = avio_seek(s->pb, e.pos, SEEK_SET);
int64_t
what level of accuracy is this code intended to have ?
seek-acodec-flac would differ by the amounts listed below if the code
would be enabled and not depend on AVFMT_FLAG_FAST_SEEK
--- ./tests/ref/seek/acodec-flac 2015-09-25 03:40:06.793930465 +0200
+++ tests/data/fate/seek-acodec-flac 2015-09-25 04:22:51.565984498 +0200
@@ -2,7 +2,7 @@
ret: 0 st:-1 flags:0 ts:-1.000000
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st:-1 flags:1 ts: 1.894167
-ret: 0 st: 0 flags:1 dts: 1.880816 pts: 1.880816 pos: 86742 size:
2191
+ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:0 ts: 0.788345
ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st: 0 flags:1 ts:-0.317506
@@ -10,44 +10,44 @@
ret: 0 st:-1 flags:0 ts: 2.576668
ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:1 ts: 1.470835
-ret: 0 st: 0 flags:1 dts: 1.462857 pts: 1.462857 pos: 53388 size:
1851
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st: 0 flags:0 ts: 0.365011
-ret: 0 st: 0 flags:1 dts: 0.365714 pts: 0.365714 pos: 16890 size:
614
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st: 0 flags:1 ts:-0.740839
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st:-1 flags:0 ts: 2.153336
-ret: 0 st: 0 flags:1 dts: 2.168163 pts: 2.168163 pos: 110531 size:
2143
+ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:1 ts: 1.047503
-ret: 0 st: 0 flags:1 dts: 1.044898 pts: 1.044898 pos: 32880 size:
579
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st: 0 flags:0 ts:-0.058322
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:1 ts: 2.835828
-ret: 0 st: 0 flags:1 dts: 2.821224 pts: 2.821224 pos: 167112 size:
2391
+ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:0 ts: 1.730004
-ret: 0 st: 0 flags:1 dts: 1.750204 pts: 1.750204 pos: 75788 size:
2191
+ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:1 ts: 0.624171
-ret: 0 st: 0 flags:1 dts: 0.600816 pts: 0.600816 pos: 22446 size:
616
+ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:0 ts:-0.481655
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:1 ts: 2.412494
-ret: 0 st: 0 flags:1 dts: 2.403265 pts: 2.403265 pos: 129793 size:
2138
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st:-1 flags:0 ts: 1.306672
-ret: 0 st: 0 flags:1 dts: 1.332245 pts: 1.332245 pos: 44812 size:
1609
+ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:1 ts: 0.200839
-ret: 0 st: 0 flags:1 dts: 0.182857 pts: 0.182857 pos: 12572 size:
628
+ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:0 ts:-0.904989
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:1 ts: 1.989184
-ret: 0 st: 0 flags:1 dts: 1.985306 pts: 1.985306 pos: 95508 size:
2169
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st:-1 flags:0 ts: 0.883340
-ret: 0 st: 0 flags:1 dts: 0.888163 pts: 0.888163 pos: 29211 size:
620
+ret: 0 st: 0 flags:1 dts: 2.586122 pts: 2.586122 pos: 145606 size:
2384
ret: 0 st:-1 flags:1 ts:-0.222493
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
ret: 0 st: 0 flags:0 ts: 2.671678
ret: 0 st: 0 flags:1 dts: 2.690612 pts: 2.690612 pos: 155154 size:
2394
ret: 0 st: 0 flags:1 ts: 1.565850
-ret: 0 st: 0 flags:1 dts: 1.541224 pts: 1.541224 pos: 59082 size:
1974
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st:-1 flags:0 ts: 0.460008
-ret: 0 st: 0 flags:1 dts: 0.470204 pts: 0.470204 pos: 19353 size:
608
+ret: 0 st: 0 flags:1 dts: 0.809796 pts: 0.809796 pos: 27366 size:
615
ret: 0 st:-1 flags:1 ts:-0.645825
ret: 0 st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos: 8256 size:
614
> + if (ret >= 0) {
> + return ret;
> + }
> + 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",
> --
> 1.7.7
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Those who are best at talking, realize last or never when they are wrong.
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