[FFmpeg-devel] [PATCH 6/7] avcodec/ass_split: assume default order when "Format:" line is not found

[Clément Bœsch]

On Sat, Oct 11, 2014 at 10:53:28PM +0200, wm4 wrote:
> On Sat, 11 Oct 2014 19:59:11 +0200
> Clément Bœsch <u at pkh.me> wrote:
> 
> > Fixes the decoding of the ASS stream in a mkv from a fansub release from
> > Coalgirls.
> > ---
> >  libavcodec/ass_split.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> > 
> > diff --git a/libavcodec/ass_split.c b/libavcodec/ass_split.c
> > index fea38e7..bd7db93 100644
> > --- a/libavcodec/ass_split.c
> > +++ b/libavcodec/ass_split.c
> > @@ -229,6 +229,20 @@ static inline const char *skip_space(const char *buf)
> >      return buf;
> >  }
> >  
> > +static int *get_default_field_orders(const ASSSection *section)
> > +{
> > +    int i;
> > +    int *order = av_malloc(FF_ARRAY_ELEMS(section->fields) * sizeof(*order));
> > +
> > +    if (!order)
> > +        return NULL;
> > +    for (i = 0; section->fields[i].name; i++)
> > +        order[i] = i;
> > +    while (i < FF_ARRAY_ELEMS(section->fields))
> > +        order[i] = -1;
> > +    return order;
> > +}
> > +
> >  static const char *ass_split_section(ASSSplitContext *ctx, const char *buf)
> >  {
> >      const ASSSection *section = &ass_sections[ctx->current_section];
> > @@ -246,7 +260,7 @@ static const char *ass_split_section(ASSSplitContext *ctx, const char *buf)
> >          } else if (section->format_header && !order) {
> >              len = strlen(section->format_header);
> >              if (strncmp(buf, section->format_header, len) || buf[len] != ':')
> > -                return NULL;
> > +                goto next_line;
> >              buf += len + 1;
> >              while (!is_eol(*buf)) {
> >                  buf = skip_space(buf);
> > @@ -269,6 +283,15 @@ static const char *ass_split_section(ASSSplitContext *ctx, const char *buf)
> >              if (!strncmp(buf, section->fields_header, len) && buf[len] == ':') {
> >                  uint8_t *ptr, *struct_ptr = realloc_section_array(ctx);
> >                  if (!struct_ptr)  return NULL;
> > +
> > +                /* No format header line found so far, assume default */
> > +                if (!order) {
> > +                    order = get_default_field_orders(section);
> > +                    if (!order)
> > +                        return NULL;
> > +                    ctx->field_order[ctx->current_section] = order;
> > +                }
> > +
> >                  buf += len + 1;
> >                  for (i=0; !is_eol(*buf) && i < *number; i++) {
> >                      int last = i == *number - 1;
> > @@ -298,6 +321,7 @@ static const char *ass_split_section(ASSSplitContext *ctx, const char *buf)
> >                      }
> >              }
> >          }
> > +next_line:
> >          buf += strcspn(buf, "\n");
> >          buf += !!*buf;
> >      }
> 
> I think you must distinguish between ASS and SSA when doing this.

It's already the case; there are two sections, one for "V4+ Styles" and
one for "V4 Styles". Both sections should have the correct fields names in
.fields after previous commit.

[...]

-- 
Clément B.
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