[FFmpeg-devel] Patch (2/2) Make MPEGTSENC understand Teletext Encoding Language String

[Clément Bœsch]

On Mon, Sep 23, 2013 at 11:52:45AM +0100, JULIAN GARDNER wrote:
> 

> From 488017a2dbc1b2489f161c7b6933fad94c1987af Mon Sep 17 00:00:00 2001
> From: Julian Gardner <joolzg at btinternet.com>
> Date: Mon, 23 Sep 2013 12:45:20 +0200
> Subject: [PATCH 3/3] Add in decoding of language field which contains the list
>  of Teletext Pages being signalled

"Subject: Re: [FFmpeg-devel] Patch (2/2) Make MPEGTSENC understand Teletext"

Hint: you can use git-send-email to avoid manually re-writing the subject
which doesn't match the title of your commit.

> 
> ---
>  libavformat/mpegtsenc.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 59 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
> index 1d51b97..55fd2f9 100644
> --- a/libavformat/mpegtsenc.c
> +++ b/libavformat/mpegtsenc.c
> @@ -372,7 +372,65 @@ static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
>              }
>              break;
>          case AVMEDIA_TYPE_SUBTITLE:
> -            {
> +        av_log( s, AV_LOG_WARNING, "SUBTITLE %p %d %s\n",
> +            st->codec->extradata, st->codec->extradata_size, lang->value);

Why a warning?

> +            if (!st->codec->extradata_size) {
> +                const char *language = lang->value;
> +                uint8_t *sizep = q + 1;
> +                uint8_t *ss;
> +                int type, page;
> +

> +                *q++ = 0x56;
> +                *q++ = 0;
> +                ss = q;
> +                while (*language) {
> +                    *q++ = *language++;
> +                    *q++ = *language++;
> +                    *q++ = *language++;

Is this safe for overflows (both for read and write)?

> +                    language++;             /* ignore comma */
> +                    switch (*language++) {
> +                    case 'R':
> +                        type = 0;   /* Reserved */
> +                        break;
> +
> +                    case 'I':       /* Inital Page */
> +                        type = 1;
> +                        break;
> +
> +                    case 'S':       /* Subtitle Page */
> +                        type = 2;
> +                        break;
> +
> +                    case 'A':       /* Additional Info Page */
> +                        type = 3;
> +                        break;
> +
> +                    case 'P':       /* Programme Schedule Page */
> +                        type = 4;
> +                        break;
> +
> +                    case 'H':       /* Subtitle For Hard Of Hearing */
> +                        type = 5;
> +                        break;
> +
> +                    default:
> +                        type = 31;   /* reserved */
> +                        break;
> +                    }
> +                    sscanf( language, "%x", &page);
> +                    language += 3;
> +                    /* 100-799 is as is, 800-899 is mapped to 000-099 */
> +                    if( page>0x7ff)
> +                        page -= 0x800;
> +                    *q++ = (type<<3) | page/256;
> +                    *q++ = page & 255;
> +                    if (*language!=',')
> +                        break;
> +                    language++;
> +                }
> +                *sizep = (q-ss);
> +            }
> +            else {

Note: your coding style is completely off in that patch as well.

-- 
Clément B.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 490 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20130923/d59d8b1b/attachment.asc>