[FFmpeg-devel] [PATCH v3] avformat/mxfdec: Read video range from PictureDescriptor

[Harry Mallon]

> On 12 Aug 2020, at 14:59, Tomas Härdin <tjoppen at acc.umu.se> wrote:
> 
> ons 2020-08-12 klockan 13:43 +0100 skrev Harry Mallon:
>> @@ -2492,6 +2504,18 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
>>             }
>>             if (descriptor->aspect_ratio.num && descriptor->aspect_ratio.den)
>>                 st->display_aspect_ratio = descriptor->aspect_ratio;
>> +            if (descriptor->component_depth &&
>> +                descriptor->black_ref_level == 0 &&
>> +                descriptor->white_ref_level == ((1<<descriptor->component_depth) - 1) &&
>> +                descriptor->color_range     == ((1<<descriptor->component_depth) - 1)) {
>> +                st->codecpar->color_range = AVCOL_RANGE_JPEG;
>> +            }
>> +            else if (descriptor->component_depth >= 8 &&
>> +                     descriptor->black_ref_level == (1  <<(descriptor->component_depth - 4)) &&
>> +                     descriptor->white_ref_level == (235<<(descriptor->component_depth - 8)) &&
>> +                     descriptor->color_range     == ((14<<(descriptor->component_depth - 4)) + 1)) {
>> +                st->codecpar->color_range = AVCOL_RANGE_MPEG;
>> +            }
> 
> Put a warning here in case levels are set but neither of these two ifs
> are true, perhaps using avpriv_request_sample(). I can imagine there's
> encoders that put off-by-one values in here. I'd like to see such files
> first though before we widen these if clauses, so we can put the
> samples in FATE.
> 
> I'm testing the previous patch. Will push that one once FATE passes.
> 
> /Tomas
> 

Thanks Tomas, here is an updated V4

>From 5866d0dc5536a6ea3f6a899c3d09f19df083c16a Mon Sep 17 00:00:00 2001
From: Harry Mallon <harry.mallon at codex.online>
Date: Wed, 12 Aug 2020 10:26:23 +0100
Subject: [PATCH v4] avformat/mxfdec: Read video range from PictureDescriptor

* Capture black_ref, white_ref and color_range and recognise
  full and narrow range.

Signed-off-by: Harry Mallon <harry.mallon at codex.online>
---
 libavformat/mxfdec.c           | 29 +++++++++++++++++++++++++++++
 tests/ref/fate/mxf-probe-dnxhd |  2 +-
 tests/ref/fate/mxf-probe-dv25  |  2 +-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 4b56984b77..0831ad5768 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -199,6 +199,9 @@ typedef struct MXFDescriptor {
     int bits_per_sample;
     int64_t duration; /* ContainerDuration optional property */
     unsigned int component_depth;
+    unsigned int black_ref_level;
+    unsigned int white_ref_level;
+    unsigned int color_range;
     unsigned int horiz_subsampling;
     unsigned int vert_subsampling;
     UID *sub_descriptors_refs;
@@ -1222,6 +1225,15 @@ static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int
     case 0x3302:
         descriptor->horiz_subsampling = avio_rb32(pb);
         break;
+    case 0x3304:
+        descriptor->black_ref_level = avio_rb32(pb);
+        break;
+    case 0x3305:
+        descriptor->white_ref_level = avio_rb32(pb);
+        break;
+    case 0x3306:
+        descriptor->color_range = avio_rb32(pb);
+        break;
     case 0x3308:
         descriptor->vert_subsampling = avio_rb32(pb);
         break;
@@ -2492,6 +2504,23 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
             }
             if (descriptor->aspect_ratio.num && descriptor->aspect_ratio.den)
                 st->display_aspect_ratio = descriptor->aspect_ratio;
+            if (descriptor->component_depth &&
+                descriptor->black_ref_level == 0 &&
+                descriptor->white_ref_level == ((1<<descriptor->component_depth) - 1) &&
+                descriptor->color_range     == ((1<<descriptor->component_depth) - 1)) {
+                st->codecpar->color_range = AVCOL_RANGE_JPEG;
+            }
+            else if (descriptor->component_depth >= 8 &&
+                     descriptor->black_ref_level == (1  <<(descriptor->component_depth - 4)) &&
+                     descriptor->white_ref_level == (235<<(descriptor->component_depth - 8)) &&
+                     descriptor->color_range     == ((14<<(descriptor->component_depth - 4)) + 1)) {
+                st->codecpar->color_range = AVCOL_RANGE_MPEG;
+            }
+            else if (descriptor->black_ref_level || descriptor->white_ref_level || descriptor->color_range) {
+                avpriv_request_sample(mxf->fc, "Unrecognized color range (range %d, b %d, w %d, depth %d)",
+                                      descriptor->color_range, descriptor->black_ref_level,
+                                      descriptor->white_ref_level, descriptor->component_depth);
+            }
             st->codecpar->color_primaries = mxf_get_codec_ul(ff_mxf_color_primaries_uls, &descriptor->color_primaries_ul)->id;
             st->codecpar->color_trc       = mxf_get_codec_ul(ff_mxf_color_trc_uls, &descriptor->color_trc_ul)->id;
             st->codecpar->color_space     = mxf_get_codec_ul(ff_mxf_color_space_uls, &descriptor->color_space_ul)->id;
diff --git a/tests/ref/fate/mxf-probe-dnxhd b/tests/ref/fate/mxf-probe-dnxhd
index 012d3ea1d9..5a6221b1d5 100644
--- a/tests/ref/fate/mxf-probe-dnxhd
+++ b/tests/ref/fate/mxf-probe-dnxhd
@@ -124,7 +124,7 @@ sample_aspect_ratio=1:1
 display_aspect_ratio=4:3
 pix_fmt=yuv422p
 level=-99
-color_range=unknown
+color_range=tv
 color_space=bt709
 color_transfer=bt709
 color_primaries=bt709
diff --git a/tests/ref/fate/mxf-probe-dv25 b/tests/ref/fate/mxf-probe-dv25
index 810f145f41..ffd26c4dfd 100644
--- a/tests/ref/fate/mxf-probe-dv25
+++ b/tests/ref/fate/mxf-probe-dv25
@@ -16,7 +16,7 @@ sample_aspect_ratio=16:15
 display_aspect_ratio=4:3
 pix_fmt=yuv420p
 level=-99
-color_range=unknown
+color_range=tv
 color_space=unknown
 color_transfer=bt470m
 color_primaries=unknown
-- 
2.28.0