[FFmpeg-devel] [PATCH 12/17] avformat/assdec: output ASS packets

[Clément Bœsch]

On Sun, Sep 21, 2014 at 08:32:59AM +0200, wm4 wrote:
> On Sat, 20 Sep 2014 22:27:52 +0200
> Clément Bœsch <u at pkh.me> wrote:
> 
> > After this the order from the original file is stored through readorder
> > when doing ffmpeg -i input.ass -c copy output.mkv.
> > 
> > And now that the ASS muxer honors the ReadOrder, extracting the ass back
> > (without transcoding) restores the original order.
> > ---
> >  libavformat/assdec.c  | 31 ++++++++++++++++++++++++-------
> >  libavformat/version.h |  2 +-
> >  2 files changed, 25 insertions(+), 8 deletions(-)
> > 
> > diff --git a/libavformat/assdec.c b/libavformat/assdec.c
> > index a5f792a..5480171 100644
> > --- a/libavformat/assdec.c
> > +++ b/libavformat/assdec.c
> > @@ -29,6 +29,7 @@
> >  
> >  typedef struct ASSContext {
> >      FFDemuxSubtitlesQueue q;
> > +    unsigned readorder;
> >  } ASSContext;
> >  
> >  static int ass_probe(AVProbeData *p)
> > @@ -52,18 +53,32 @@ static int ass_read_close(AVFormatContext *s)
> >      return 0;
> >  }
> >  
> > -static int read_ts(const uint8_t *p, int64_t *start, int *duration)
> > +static void rstrip_buf(AVBPrint *buf)
> > +{
> > +    while (buf->len > 0 &&
> > +           buf->str[buf->len - 1] == '\r' ||
> > +           buf->str[buf->len - 1] == '\n')
> > +        buf->str[--buf->len] = 0;
> > +}
> > +
> > +static int read_dialogue(ASSContext *ass, AVBPrint *dst, const uint8_t *p,
> > +                         int64_t *start, int *duration)
> >  {
> >      int64_t end;
> > +    int layer, pos;
> >      int hh1, mm1, ss1, ms1;
> >      int hh2, mm2, ss2, ms2;
> >  
> > -    if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
> > +    if (sscanf(p, "Dialogue: %d,%d:%d:%d%*c%d,%d:%d:%d%*c%d,%n", &layer,
> >                 &hh1, &mm1, &ss1, &ms1,
> > -               &hh2, &mm2, &ss2, &ms2) == 8) {
> > +               &hh2, &mm2, &ss2, &ms2, &pos) >= 9) {
> >          end    = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
> >          *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
> >          *duration = end - *start;
> > +
> > +        av_bprint_clear(dst);
> > +        av_bprintf(dst, "%u,%d,%s", ass->readorder++, layer, p + pos);
> > +        rstrip_buf(dst);
> >          return 0;
> >      }
> >      return -1;
> > @@ -88,7 +103,7 @@ static int64_t get_line(AVBPrint *buf, FFTextReader *tr)
> >  static int ass_read_header(AVFormatContext *s)
> >  {
> >      ASSContext *ass = s->priv_data;
> > -    AVBPrint header, line;
> > +    AVBPrint header, line, rline;
> >      int header_remaining, res = 0;
> >      AVStream *st;
> >      FFTextReader tr;
> > @@ -99,12 +114,13 @@ static int ass_read_header(AVFormatContext *s)
> >          return AVERROR(ENOMEM);
> >      avpriv_set_pts_info(st, 64, 1, 100);
> >      st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
> > -    st->codec->codec_id   = AV_CODEC_ID_SSA;
> > +    st->codec->codec_id   = AV_CODEC_ID_ASS;
> >  
> >      header_remaining = INT_MAX;
> >  
> >      av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
> >      av_bprint_init(&line,   0, AV_BPRINT_SIZE_UNLIMITED);
> > +    av_bprint_init(&rline,  0, AV_BPRINT_SIZE_UNLIMITED);
> >  
> >      for (;;) {
> >          int64_t pos = get_line(&line, &tr);
> > @@ -125,9 +141,9 @@ static int ass_read_header(AVFormatContext *s)
> >              int duration = -1;
> >              AVPacket *sub;
> >  
> > -            if (read_ts(line.str, &ts_start, &duration) < 0)
> > +            if (read_dialogue(ass, &rline, line.str, &ts_start, &duration) < 0)
> >                  continue;
> > -            sub = ff_subtitles_queue_insert(&ass->q, line.str, line.len, 0);
> > +            sub = ff_subtitles_queue_insert(&ass->q, rline.str, rline.len, 0);
> >              if (!sub) {
> >                  res = AVERROR(ENOMEM);
> >                  goto end;
> > @@ -139,6 +155,7 @@ static int ass_read_header(AVFormatContext *s)
> >      }
> >  
> >      av_bprint_finalize(&line, NULL);
> > +    av_bprint_finalize(&rline, NULL);
> >  
> >      res = avpriv_bprint_to_extradata(st->codec, &header);
> >      if (res < 0)
> > diff --git a/libavformat/version.h b/libavformat/version.h
> > index a869602..61decb9 100644
> > --- a/libavformat/version.h
> > +++ b/libavformat/version.h
> > @@ -31,7 +31,7 @@
> >  
> >  #define LIBAVFORMAT_VERSION_MAJOR 56
> >  #define LIBAVFORMAT_VERSION_MINOR  4
> > -#define LIBAVFORMAT_VERSION_MICRO 102
> > +#define LIBAVFORMAT_VERSION_MICRO 103
> >  
> >  #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
> >                                                 LIBAVFORMAT_VERSION_MINOR, \
> 
> I think this was ok.

Note: I still haven't pushed this because it breaks when line are in old
ASS (with Marked=0 prefix). I'll fix that ASAP.

-- 
Clément B.
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