[FFmpeg-devel] [PATCH] avformat/mxfdec: Detect XYZ pixel format for digital cinema files

Tomas Härdin tomas.hardin at codemill.se
Thu Mar 5 11:41:35 CET 2015


On Thu, 2015-03-05 at 00:36 +0200, Vilius Grigaliūnas wrote:
> While the native jpeg2000 decoder can determine pixel format correctly
> from the codestream, libopenjpeg wrapper cannot. To make sure that
> the output is correct when using libopenjpeg to decode digital
> cinema files, we do detection from the metadata included in the MXF
> wrapper.
> 
> If the container has "JPEG 2000 Coding Parameters" metadata element
> with Rsiz value set to one of digital cinema profiles, we can safely
> assume that the given input file is DCI compliant, therefore the
> pixel format should be XYZ.
> ---
>  libavformat/mxfdec.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index f3501da..2e8dd05 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -281,6 +281,7 @@ static const uint8_t mxf_encrypted_essence_container[]     = { 0x06,0x0e,0x2b,0x
>  static const uint8_t mxf_random_index_pack_key[]           = { 0x06,0x0e,0x2b,0x34,0x02,0x05,0x01,0x01,0x0d,0x01,0x02,0x01,0x01,0x11,0x01,0x00 };
>  static const uint8_t mxf_sony_mpeg4_extradata[]            = { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x01,0x0e,0x06,0x06,0x02,0x02,0x01,0x00,0x00 };
>  static const uint8_t mxf_avid_project_name[]               = { 0xa5,0xfb,0x7b,0x25,0xf6,0x15,0x94,0xb9,0x62,0xfc,0x37,0x17,0x49,0x2d,0x42,0xbf };
> +static const uint8_t mxf_jp2k_rsiz[]                       = { 0x06,0x0e,0x2b,0x34,0x02,0x05,0x01,0x01,0x0d,0x01,0x02,0x01,0x01,0x02,0x01,0x00 };
>  
>  #define IS_KLV_KEY(x, y) (!memcmp(x, y, sizeof(y)))
>  
> @@ -1000,6 +1001,12 @@ static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int
>              descriptor->extradata_size = size;
>              avio_read(pb, descriptor->extradata, size);
>          }
> +        if (IS_KLV_KEY(uid, mxf_jp2k_rsiz)) {
> +            uint32_t rsiz = avio_rb16(pb);
> +            if (rsiz == FF_PROFILE_JPEG2000_DCINEMA_2K ||
> +                rsiz == FF_PROFILE_JPEG2000_DCINEMA_4K)
> +                descriptor->pix_fmt = AV_PIX_FMT_XYZ12;
> +        }
>          break;
>      }
>      return 0;

Nice, simple and commit message explains exactly what is going on.
10/10 :)

Is there a sample file so this can be covered by FATE?

/Tomas
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