[FFmpeg-devel] [PATCH 4/4] dnxhddec: parse and print adaptive color transform

[Christophe Gisquet]

Indicates a YCbCr->RGB transform at the block level. Although nothing
explicitly states it, this would assume the actual content is planar
RGB.

Currently unsupported, but the one sequence I found using it flagged
every mb that way, actually meaning the content was YCbCr, and thus
best left to the output format to decide what to do of it.
---
 libavcodec/dnxhddec.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index 82a0d3c..7570a9a 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -59,6 +59,7 @@ typedef struct DNXHDContext {
     int bit_depth; // 8, 10 or 0 if not initialized at all.
     int is_444;
     int mbaff;
+    int act;
     void (*decode_dct_block)(const struct DNXHDContext *ctx,
                              RowContext *row, int16_t *block,
                              int n, int qscale);
@@ -198,6 +199,11 @@ static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,
         av_log(ctx->avctx, AV_LOG_WARNING,
                "Adaptive MB interlace flag in an unsupported profile.\n");
 
+    ctx->act = buf[0x2C] & 7;
+    if (ctx->act && ctx->cid_table->cid != 1256)
+        av_log(ctx->avctx, AV_LOG_WARNING,
+               "Adaptive color transform in an unsupported profile.\n");
+
     // make sure profile size constraints are respected
     // DNx100 allows 1920->1440 and 1280->960 subsampling
     if (ctx->width != ctx->cid_table->width) {
@@ -368,7 +374,7 @@ static int dnxhd_decode_macroblock(const DNXHDContext *ctx, RowContext *row,
     int dct_linesize_chroma = frame->linesize[1];
     uint8_t *dest_y, *dest_u, *dest_v;
     int dct_y_offset, dct_x_offset;
-    int qscale, i;
+    int qscale, i, act;
     int interlaced_mb = 0;
 
     if (ctx->mbaff) {
@@ -376,7 +382,15 @@ static int dnxhd_decode_macroblock(const DNXHDContext *ctx, RowContext *row,
         qscale = get_bits(&row->gb, 10);
     } else
         qscale = get_bits(&row->gb, 11);
-    skip_bits1(&row->gb);
+    act = get_bits1(&row->gb);
+    if (act) {
+        static int warned = 0;
+        if (!warned) {
+            warned = 1;
+            av_log(ctx->avctx, AV_LOG_ERROR,
+                   "Unsupported adaptive color transform, patch welcome.\n");
+        }
+    }
 
     if (qscale != row->last_qscale) {
         for (i = 0; i < 64; i++) {
-- 
2.5.3.windows.1