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

[Vilius Grigaliūnas]

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;
-- 
1.7.9.5