[FFmpeg-devel] Patch (1/2) Decoding of Teletext Descriptor (0x56)

[Clément Bœsch]

On Mon, Sep 23, 2013 at 11:52:31AM +0100, JULIAN GARDNER wrote:
> Hope these work, please let me know of any problems

> From 650e40c5e2856656bf2f807ae81a275ee0bc647a Mon Sep 17 00:00:00 2001
> From: Julian Gardner <joolzg at btinternet.com>
> Date: Mon, 23 Sep 2013 12:44:41 +0200
> Subject: [PATCH 2/3] Add in decoding of Teletext Subtitles Descriptor (0x56)
> 
> ---
>  libavformat/mpegts.c | 32 ++++++++++++++++++++++++++------
>  1 file changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index 2e438fd..1eab5e2 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -1404,7 +1404,7 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
>      const uint8_t *desc_end;
>      int desc_len, desc_tag, desc_es_id;
>      char language[252];
> -    int i;
> +    int i, l;
>  
>      desc_tag = get8(pp, desc_list_end);
>      if (desc_tag < 0)
> @@ -1457,10 +1457,30 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
>          }
>          break;
>      case 0x56: /* DVB teletext descriptor */
> -        language[0] = get8(pp, desc_end);
> -        language[1] = get8(pp, desc_end);
> -        language[2] = get8(pp, desc_end);
> -        language[3] = 0;
> +        for (i = l = 0; i + 5 <= desc_len; i += 5) {
> +        int type, mag, page;
> +        int l0, l1, l2;
> +        static const char types[] = "RISAPH";
> +
> +            l0 = get8(pp, desc_end);
> +            l1 = get8(pp, desc_end);
> +            l2 = get8(pp, desc_end);
> +            type = get8(pp, desc_end);
> +            page = get8(pp, desc_end);
> +            if (l<(sizeof( language) - 9)) {
> +                mag = type;
> +                type >>= 3;
> +                if (type < sizeof( types)) {
> +                    mag &= 7; if (!mag) mag = 8;
> +                    sprintf( language+l, "%c%c%c,%c%d%02x,", l0, l1,
> +                        l2, types[ type], mag, page);

use snprintf, the your if don't look safe enougth to me.

> +                    l += 9;
> +                }
> +            }
> +        }

> +        if( l) {
> +            language[ l - 1] = 0;
> +        }

Is this necessary?

Also, please fix your style it's all broken; indent, random spaces
inconsistently badly placed, etc.

>          av_dict_set(&st->metadata, "language", language, 0);
>          break;
>      case 0x59: /* subtitling descriptor */
> @@ -1979,7 +1999,7 @@ static int read_packet(AVFormatContext *s, uint8_t *buf, int raw_packet_size, co
>      return 0;
>  }
>  

> -static void finished_reading_packet(AVFormatContext *s, int raw_packet_size)
> +static inline void finished_reading_packet(AVFormatContext *s, int raw_packet_size)

Why?

[...]

-- 
Clément B.
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