vd_lavc: decode embedded ICC profiles

Since these need to be refcounted, we throw them directly into struct
mp_image instead of being part of mp_colorspace. Even though they would
semantically make more sense in mp_colorspace, having them there is
really awkward because mp_colorspace is passed around and stored a lot,
and this way their lifetime is exactly tied to the lifetime of the
mp_image associated with it.

video/decode/vd_lavc.c

@@ -1184,6 +1184,12 @@ static bool decode_frame(struct dec_video *vd)
         mp_pts_from_av(av_frame_get_pkt_duration(ctx->pic), &ctx->codec_timebase);
 #endif
 
+#if HAVE_AVUTIL_ICC_PROFILE
+    sd = av_frame_get_side_data(ctx->pic, AV_FRAME_DATA_ICC_PROFILE);
+    if (sd)
+        mpi->icc_profile = av_buffer_ref(sd->buf);
+#endif
+
     update_image_params(vd, ctx->pic, &mpi->params);
 
     av_frame_unref(ctx->pic);

video/mp_image.c

@@ -200,6 +200,7 @@ static void mp_image_destructor(void *ptr)
     for (int p = 0; p < MP_MAX_PLANES; p++)
         av_buffer_unref(&mpi->bufs[p]);
     av_buffer_unref(&mpi->hwctx);
+    av_buffer_unref(&mpi->icc_profile);
 }
 
 int mp_chroma_div_up(int size, int shift)
@@ -316,6 +317,12 @@ struct mp_image *mp_image_new_ref(struct mp_image *img)
             fail = true;
     }
 
+    if (new->icc_profile) {
+        new->icc_profile = av_buffer_ref(new->icc_profile);
+        if (!new->icc_profile)
+            fail = true;
+    }
+
     if (!fail)
         return new;
 
@@ -525,6 +532,13 @@ void mp_image_copy_attributes(struct mp_image *dst, struct mp_image *src)
                 memcpy(dst->planes[1], src->planes[1], MP_PALETTE_SIZE);
         }
     }
+    av_buffer_unref(&dst->icc_profile);
+    dst->icc_profile = src->icc_profile;
+    if (dst->icc_profile) {
+        dst->icc_profile = av_buffer_ref(dst->icc_profile);
+        if (!dst->icc_profile)
+            abort();
+    }
 }
 
 // Crop the given image to (x0, y0)-(x1, y1) (bottom/right border exclusive)

video/mp_image.h

@@ -100,6 +100,8 @@ typedef struct mp_image {
     struct AVBufferRef *bufs[MP_MAX_PLANES];
     // Points to AVHWFramesContext* (same as AVFrame.hw_frames_ctx)
     struct AVBufferRef *hwctx;
+    // Embedded ICC profile, if any
+    struct AVBufferRef *icc_profile;
 } mp_image_t;
 
 int mp_chroma_div_up(int size, int shift);

wscript

@@ -461,6 +461,12 @@ FFmpeg/Libav libraries. You need at least {0}. Aborting.".format(libav_versions_
         'func': check_statement('libavutil/frame.h',
                                 'AV_FRAME_DATA_CONTENT_LIGHT_LEVEL',
                                 use='libav'),
+    }, {
+        'name': 'avutil-icc-profile',
+        'desc': 'libavutil ICC profile side data',
+        'func': check_statement('libavutil/frame.h',
+                                'AV_FRAME_DATA_ICC_PROFILE',
+                                use='libav'),
     },
 ]