[vlc-devel] [PATCH] modules/codec/omxil/mediacodec.c: add MPEG2 support

[Steve Lhomme]

It seems your patch does 2 things. Can you split it in two ? Probably 
the aspect ratio fix should come first if the MPEG2 decoder cannot work 
without that.


Le 16/02/2018 à 11:04, Alexandre Janniaux a écrit :
> Add MPEG2 support with Mediacodec on Android, fixing the aspect ratio
> inside of the mediacodec_ndk submodule. It extracts the
> aspect_ratio_information from any block containing a SEQUENCE_HEADER
> and applies it in the UpdateVout function.
> ---
>   modules/codec/omxil/mediacodec.c | 70 ++++++++++++++++++++++++++++++++--------
>   1 file changed, 57 insertions(+), 13 deletions(-)
>
> diff --git a/modules/codec/omxil/mediacodec.c b/modules/codec/omxil/mediacodec.c
> index cb6a72868c..57a3f532fd 100644
> --- a/modules/codec/omxil/mediacodec.c
> +++ b/modules/codec/omxil/mediacodec.c
> @@ -121,6 +121,7 @@ struct decoder_sys_t
>               picture_sys_t** pp_inflight_pictures;
>               unsigned int i_inflight_pictures;
>               timestamp_fifo_t *timestamp_fifo;
> +            int i_mpeg_dar_num, i_mpeg_dar_den;
>           } video;
>           struct {
>               date_t i_end_date;
> @@ -143,6 +144,7 @@ static void CloseDecoder(vlc_object_t *);
>   
>   static int Video_OnNewBlock(decoder_t *, block_t **);
>   static int VideoHXXX_OnNewBlock(decoder_t *, block_t **);
> +static int VideoMPEG2_OnNewBlock(decoder_t *, block_t **);
>   static int VideoVC1_OnNewBlock(decoder_t *, block_t **);
>   static void Video_OnFlush(decoder_t *);
>   static int Video_ProcessOutput(decoder_t *, mc_api_out *, picture_t **,
> @@ -422,20 +424,33 @@ static int ParseExtra(decoder_t *p_dec)
>       case VLC_CODEC_MP4V:
>           if (!i_extra && p_sys->api.i_quirks & MC_API_VIDEO_QUIRKS_ADAPTIVE)
>               p_sys->b_adaptive = true;
> -        /* fall through */
> -    default:
> -        /* Set default CSD */
> -        if (p_dec->fmt_in.i_extra)
> -            return CSDDup(p_dec, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra);
> -        else
> -            return VLC_SUCCESS;
> +        break;
> +    case VLC_CODEC_MPGV:
> +    case VLC_CODEC_MP2V:
> +        p_dec->p_sys->pf_on_new_block = VideoMPEG2_OnNewBlock;
> +        break;
>       }
> +    /* Set default CSD */
> +    if (p_dec->fmt_in.i_extra)
> +        return CSDDup(p_dec, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra);
> +    else
> +        return VLC_SUCCESS;
>   }
>   
>   static int UpdateVout(decoder_t *p_dec)
>   {
>       decoder_sys_t *p_sys = p_dec->p_sys;
>   
> +    if ((p_dec->fmt_in.i_codec == VLC_CODEC_MPGV ||
> +        p_dec->fmt_in.i_codec == VLC_CODEC_MP2V) &&
> +        p_sys->video.i_mpeg_dar_num * p_sys->video.i_mpeg_dar_den != 0)
> +    {
> +        p_dec->fmt_out.video.i_sar_num =
> +            p_sys->video.i_mpeg_dar_num * p_dec->fmt_out.video.i_height;
> +        p_dec->fmt_out.video.i_sar_den =
> +            p_sys->video.i_mpeg_dar_den * p_dec->fmt_out.video.i_width;
> +    }
> +
>       /* If MediaCodec can handle the rotation, reset the orientation to
>        * Normal in order to ask the vout not to rotate. */
>       if (p_sys->video.i_angle != 0)
> @@ -563,16 +578,14 @@ static int OpenDecoder(vlc_object_t *p_this, pf_MediaCodecApi_init pf_init)
>               break;
>           case VLC_CODEC_H263: mime = "video/3gpp"; break;
>           case VLC_CODEC_MP4V: mime = "video/mp4v-es"; break;
> +        case VLC_CODEC_MPGV:
> +        case VLC_CODEC_MP2V:
> +            mime = "video/mpeg2";
> +            break;
>           case VLC_CODEC_WMV3: mime = "video/x-ms-wmv"; break;
>           case VLC_CODEC_VC1:  mime = "video/wvc1"; break;
>           case VLC_CODEC_VP8:  mime = "video/x-vnd.on2.vp8"; break;
>           case VLC_CODEC_VP9:  mime = "video/x-vnd.on2.vp9"; break;
> -        /* FIXME: mpeg2 is disabled: sar num/den can't be updated from
> -         * MediaCodec. Use avcodec instead that will update it. The proper
> -         * solution is to update sar from a mpeg2 packetizer.
> -         *
> -         * case VLC_CODEC_MPGV: mime = "video/mpeg2"; break;
> -         */
>           }
>       }
>       else
> @@ -614,6 +627,8 @@ static int OpenDecoder(vlc_object_t *p_this, pf_MediaCodecApi_init pf_init)
>       p_sys->api.i_codec = p_dec->fmt_in.i_codec;
>       p_sys->api.i_cat = p_dec->fmt_in.i_cat;
>       p_sys->api.psz_mime = mime;
> +    p_sys->video.i_mpeg_dar_num = 0;
> +    p_sys->video.i_mpeg_dar_den = 0;
>   
>       if (pf_init(&p_sys->api) != 0)
>       {
> @@ -1582,6 +1597,35 @@ static int VideoHXXX_OnNewBlock(decoder_t *p_dec, block_t **pp_block)
>       return Video_OnNewBlock(p_dec, pp_block);
>   }
>   
> +static int VideoMPEG2_OnNewBlock(decoder_t *p_dec, block_t **pp_block)
> +{
> +    if (pp_block == NULL || (*pp_block)->i_buffer <= 7)
> +        return Video_OnNewBlock(p_dec, pp_block);
> +
> +    decoder_sys_t *p_sys = p_dec->p_sys;
> +    const int startcode = (*pp_block)->p_buffer[3];
> +
> +    static const int mpeg2_aspect[16][2] =
> +    {
> +        {0,0}, {1,1}, {4,3}, {16,9}, {221,100},
> +        {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0},
> +        {0,0}, {0,0}
> +    };
> +
> +    if (startcode == 0xB3 /* SEQUENCE_HEADER_STARTCODE */)
> +    {
> +        int mpeg_dar_code = (*pp_block)->p_buffer[7] >> 4;
> +
> +        if (mpeg_dar_code >= 16)
> +            return Video_OnNewBlock(p_dec, pp_block);
> +
> +        p_sys->video.i_mpeg_dar_num = mpeg2_aspect[mpeg_dar_code][0];
> +        p_sys->video.i_mpeg_dar_den = mpeg2_aspect[mpeg_dar_code][1];
> +    }
> +
> +    return Video_OnNewBlock(p_dec, pp_block);
> +}
> +
>   static int VideoVC1_OnNewBlock(decoder_t *p_dec, block_t **pp_block)
>   {
>       block_t *p_block = *pp_block;