[FFmpeg-devel] [PATCH] CD+G Demuxer & Decoder

[Vitor Sessak]

Michael Niedermayer wrote:
> On Tue, Dec 15, 2009 at 07:56:33PM -0800, Michael Tison wrote:
>> Revised patch attached.
>>
>> On Tue, Dec 15, 2009 at 2:06 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>>> On Mon, Dec 14, 2009 at 06:40:17PM -0800, Michael Tison wrote:
>>> [...]
>>>> +    h_off =  FFMIN(data[1] & 0x07, CDG_BORDER_WIDTH  - 1);
>>>> +    v_off =  FFMIN(data[2] & 0x07, CDG_BORDER_HEIGHT - 1);
>>>> +
>>>> +    /// find the difference and save the offset for cdg_tile_block usage
>>>> +    dh_off = h_off - cc->hscroll;
>>>> +    dv_off = v_off - cc->vscroll;
>>>> +    cc->hscroll = h_off;
>>>> +    cc->vscroll = v_off;
>>>> +
>>>> +    if (vscmd == UP)
>>>> +        vinc = -12;
>>>> +    if (vscmd == DOWN)
>>>> +        vinc = 12;
>>>> +    if (hscmd == LEFT)
>>>> +        hinc = -6;
>>>> +    if (hscmd == RIGHT)
>>>> +        hinc = 6;
>>>> +    vinc += dv_off;
>>>> +    hinc += dh_off;
>>>> +
>>>> +    if (!hinc && !vinc)
>>>> +        return;
>>> if (vscmd == UP)
>>>    dv_off -= 12;
>>> if (vscmd == DOWN)
>>>    dv_off += 12;
>>> ...
>>> if(!vscmd && !hscmd) (or ==3 i dont know which is the do nothing case)
>>>    return
>> Compacted.
>>
>>> [...]
>>>> +static int read_header(AVFormatContext *s, AVFormatParameters *ap)
>>>> +{
>>>> +    AVStream *vst;
>>>> +    int ret;
>>>> +
>>>> +    vst = av_new_stream(s, 0);
>>>> +    if (!vst)
>>>> +        return AVERROR(ENOMEM);
>>>> +
>>>> +    vst->codec->codec_type = CODEC_TYPE_VIDEO;
>>>> +    vst->codec->codec_id   = CODEC_ID_CDGRAPHICS;
>>>> +
>>>> +    /// 75 sectors/sec * 4 packets/sector = 300 packets/sec
>>>> +    av_set_pts_info(vst, 32, 1, 300);
>>>> +
>>>> +    ret = url_fsize(s->pb);
>>>> +    if (ret < 0)
>>>> +        return ret;
>>> i think failing in this case is unreasonable
>> Okay makes sense.
>>
>> Michael
> 
>>  Changelog                |    1 
>>  doc/general.texi         |    4 
>>  libavcodec/Makefile      |    1 
>>  libavcodec/allcodecs.c   |    1 
>>  libavcodec/avcodec.h     |    1 
>>  libavcodec/cdgraphics.c  |  380 +++++++++++++++++++++++++++++++++++++++++++++++
>>  libavformat/Makefile     |    1 
>>  libavformat/allformats.c |    1 
>>  libavformat/avformat.h   |    2 
>>  libavformat/cdg.c        |   66 ++++++++
>>  10 files changed, 457 insertions(+), 1 deletion(-)
>> ac5acde84756bac6aedb65f2583adcc870d7b60b  cdgraphicsv9.patch
> 
> looks ok assuming its tested & works (test against some fuzzer without
> it crashing is probably also a good idea)

Tested with two samples and tools/trasher and applied.

-Vitor