[FFmpeg-devel] [PATCH] avcodec/webvttdec: Deal with WebVTT escapes

[Clément Bœsch]

On Fri, Oct 09, 2015 at 04:29:03PM +0100, Ricardo Constantino wrote:
> Bare ampersand characters are still accepted, even though out-of-spec.
> Also fixes adjacent tags not being parsed.
> 
> Fixes trac #4915
> 
> Signed-off-by: Ricardo Constantino <wiiaboo at gmail.com>
> ---
>  libavcodec/webvttdec.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/webvttdec.c b/libavcodec/webvttdec.c
> index 1284a17..3b98e98 100644
> --- a/libavcodec/webvttdec.c
> +++ b/libavcodec/webvttdec.c
> @@ -37,11 +37,14 @@ static const struct {
>      {"<b>", "{\\b1}"}, {"</b>", "{\\b0}"},
>      {"<u>", "{\\u1}"}, {"</u>", "{\\u0}"},
>      {"{", "\\{"}, {"}", "\\}"}, // escape to avoid ASS markup conflicts
> +    {">", ">"}, {"<", "<"},
> +    {"‎", ""}, {"‏", ""}, // FIXME: properly honor bidi marks

> +    {"&", "&"}, {" ", " "},

nbsp → \h in ASS

See http://docs.aegisub.org/3.2/ASS_Tags/

>  };
>  
>  static int webvtt_event_to_ass(AVBPrint *buf, const char *p)
>  {
> -    int i, skip = 0;
> +    int i, again, skip = 0;
>  
>      while (*p) {
>  
> @@ -51,13 +54,19 @@ static int webvtt_event_to_ass(AVBPrint *buf, const char *p)
>              if (!strncmp(p, from, len)) {
>                  av_bprintf(buf, "%s", webvtt_tag_replace[i].to);
>                  p += len;
> +                again = 1;
>                  break;
>              }
>          }
>          if (!*p)
>              break;
>  
> -        if (*p == '<')
> +        if (again) {
> +            again = 0;
> +            skip = 0;
> +            continue;
> +        }

> +        else if (*p == '<')

nit: this else can be kept away to keep the diff small.

[...]

-- 
Clément B.
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