[FFmpeg-devel] [PATCH 3/5] avformat/mp3dec: allow enabling generic seek mode
wm4
nfxjfg at googlemail.com
Tue Apr 21 22:16:22 CEST 2015
On Tue, 21 Apr 2015 22:07:07 +0200
Clément Bœsch <u at pkh.me> wrote:
> On Tue, Apr 21, 2015 at 09:33:52PM +0200, wm4 wrote:
> > "-usetoc 2" now invokes the generic seek and indexing mode. This mode
> > skips data until the seek target is reached, and this is exact. It also
> > makes gapless audio actually work if a seek past the start of the file
> > is involved.
> > ---
> > Strange option value. On the other hand, it will be made default, so
> > this option will generally be used only to select the "old" seek modes.
> > But in general, libavformat should probably have something to switch
> > between slow/accurate and fast/inaccurate seeking.
> > ---
> > libavformat/mp3dec.c | 12 +++++++++---
> > tests/fate/gapless.mak | 5 +++--
> > tests/ref/fate/gapless-mp3 | 5 -----
> > tests/ref/fate/gapless-mp3-cbr | 5 +++++
> > 4 files changed, 17 insertions(+), 10 deletions(-)
> > delete mode 100644 tests/ref/fate/gapless-mp3
> > create mode 100644 tests/ref/fate/gapless-mp3-cbr
> >
> > diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
> > index 008cb23..8a4dfbd 100644
> > --- a/libavformat/mp3dec.c
> > +++ b/libavformat/mp3dec.c
> > @@ -110,7 +110,7 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration
> > {
> > int i;
> > MP3DecContext *mp3 = s->priv_data;
> > - int fill_index = mp3->usetoc && duration > 0;
> > + int fill_index = mp3->usetoc == 1 && duration > 0;
> >
> > if (!filesize &&
> > !(filesize = avio_size(s->pb))) {
> > @@ -336,6 +336,9 @@ static int mp3_read_header(AVFormatContext *s)
> > int ret;
> > int i;
> >
> > + if (mp3->usetoc < 0)
> > + mp3->usetoc = 0;
> > +
> > st = avformat_new_stream(s, NULL);
> > if (!st)
> > return AVERROR(ENOMEM);
> > @@ -432,8 +435,11 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
> > int64_t best_pos;
> > int best_score;
> >
> > + if (mp3->usetoc == 2)
> > + return -1; // generic index code
> > +
> > if ( mp3->is_cbr
> > - && (mp3->usetoc <= 0 || !mp3->xing_toc)
> > + && (mp3->usetoc == 0 || !mp3->xing_toc)
> > && st->duration > 0
> > && mp3->header_filesize > s->internal->data_offset
> > && mp3->frames) {
> > @@ -498,7 +504,7 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
> > }
> >
> > static const AVOption options[] = {
> > - { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
> > + { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 2, AV_OPT_FLAG_DECODING_PARAM},
>
> Can you use AV_OPT_TYPE_CONST for the different special values?
>
> (and document it)
>
> [...]
>
I'm not sure if it's a good idea to set this in stone. I'd much rather
have something similar to AVFMT_FLAG_IGNIDX, which can be checked by
all demuxers.
More information about the ffmpeg-devel
mailing list