lavc: add a decoder option for configuring side data preference

This and the following commits fix #10857

4 files changed, 72 insertions, 0 deletions

diff --git a/doc/APIchanges b/doc/APIchanges
index 3209614ed6..5d8585d8ba 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2024-02-xx - xxxxxxxxxx - lavc 60.xx.100 - avcodec.h
+  Add AVCodecContext.[nb_]side_data_prefer_global.
+
 2024-02-xx - xxxxxxxxxx - lavu 58.xx.100 - opt.h
   Add AV_OPT_TYPE_FLAG_ARRAY and AVOptionArrayDef.
 
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 43859251cc..307a3e99db 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -2120,6 +2120,26 @@ typedef struct AVCodecContext {
      *   an error.
      */
     int64_t frame_num;
+
+    /**
+     * Decoding only. May be set by the caller before avcodec_open2() to an
+     * av_malloc()'ed array (or via AVOptions). Owned and freed by the decoder
+     * afterwards.
+     *
+     * By default, when some side data type is present both in global
+     * user-supplied coded_side_data and inside the coded bitstream, avcodec
+     * will propagate the latter to the decoded frame.
+     *
+     * This array contains a list of AVPacketSideDataType for which this
+     * preference should be switched, i.e. avcodec will prefer global side data
+     * over those in stored in the bytestream. It may also contain a single -1,
+     * in which case the preference is switched for all side data types.
+     */
+    int        *side_data_prefer_global;
+    /**
+     * Number of entries in side_data_prefer_global.
+     */
+    unsigned nb_side_data_prefer_global;
 } AVCodecContext;
 
 /**
diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 7c67b18bc4..5c80ef9cd0 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -60,6 +60,12 @@ typedef struct DecodeContext {
      * The caller has submitted a NULL packet on input.
      */
     int draining_started;
+
+    /**
+     * Bitmask indicating for which side data types we prefer global
+     * side data over per-packet.
+     */
+    uint64_t side_data_pref_mask;
 } DecodeContext;
 
 static DecodeContext *decode_ctx(AVCodecInternal *avci)
@@ -1744,6 +1750,7 @@ int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
 int ff_decode_preinit(AVCodecContext *avctx)
 {
     AVCodecInternal *avci = avctx->internal;
+    DecodeContext     *dc = decode_ctx(avci);
     int ret = 0;
 
     /* if the decoder init function was already called previously,
@@ -1804,6 +1811,35 @@ int ff_decode_preinit(AVCodecContext *avctx)
         avctx->export_side_data |= AV_CODEC_EXPORT_DATA_MVS;
     }
 
+    if (avctx->nb_side_data_prefer_global == 1 &&
+        avctx->side_data_prefer_global[0] == -1)
+        dc->side_data_pref_mask = ~0ULL;
+    else {
+        for (unsigned i = 0; i < avctx->nb_side_data_prefer_global; i++) {
+            int val = avctx->side_data_prefer_global[i];
+
+            if (val < 0 || val >= AV_PKT_DATA_NB) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid side data type: %d\n", val);
+                return AVERROR(EINVAL);
+            }
+
+            for (unsigned j = 0; j < FF_ARRAY_ELEMS(sd_global_map); j++) {
+                if (sd_global_map[j].packet == val) {
+                    val = sd_global_map[j].frame;
+
+                    // this code will need to be changed when we have more than
+                    // 64 frame side data types
+                    if (val >= 64) {
+                        av_log(avctx, AV_LOG_ERROR, "Side data type too big\n");
+                        return AVERROR_BUG;
+                    }
+
+                    dc->side_data_pref_mask |= 1ULL << val;
+                }
+            }
+        }
+    }
+
     avci->in_pkt         = av_packet_alloc();
     avci->last_pkt_props = av_packet_alloc();
     if (!avci->in_pkt || !avci->last_pkt_props)
diff --git a/libavcodec/options_table.h b/libavcodec/options_table.h
index ac32d8928a..3ff03d1cf0 100644
--- a/libavcodec/options_table.h
+++ b/libavcodec/options_table.h
@@ -42,6 +42,8 @@
 #define D AV_OPT_FLAG_DECODING_PARAM
 #define CC AV_OPT_FLAG_CHILD_CONSTS
 
+#define AR AV_OPT_TYPE_FLAG_ARRAY
+
 #define AV_CODEC_DEFAULT_BITRATE 200*1000
 
 static const AVOption avcodec_options[] = {
@@ -405,6 +407,17 @@ static const AVOption avcodec_options[] = {
 {"unsafe_output", "allow potentially unsafe hwaccel frame output that might require special care to process successfully", 0, AV_OPT_TYPE_CONST, {.i64 = AV_HWACCEL_FLAG_UNSAFE_OUTPUT }, INT_MIN, INT_MAX, V | D, .unit = "hwaccel_flags"},
 {"extra_hw_frames", "Number of extra hardware frames to allocate for the user", OFFSET(extra_hw_frames), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, V|D },
 {"discard_damaged_percentage", "Percentage of damaged samples to discard a frame", OFFSET(discard_damaged_percentage), AV_OPT_TYPE_INT, {.i64 = 95 }, 0, 100, V|D },
+{"side_data_prefer_global", "Comma-separated list of side data types for which global headers are preferred over frame-level data",
+    OFFSET(side_data_prefer_global), AV_OPT_TYPE_INT | AR, .min = -1, .max = INT_MAX, .flags = V|A|S|D, .unit = "side_data_pkt" },
+    {"replaygain",                  .default_val.i64 = AV_PKT_DATA_REPLAYGAIN,                  .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"displaymatrix",               .default_val.i64 = AV_PKT_DATA_DISPLAYMATRIX,               .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"spherical",                   .default_val.i64 = AV_PKT_DATA_SPHERICAL,                   .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"stereo3d",                    .default_val.i64 = AV_PKT_DATA_STEREO3D,                    .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"audio_service_type",          .default_val.i64 = AV_PKT_DATA_AUDIO_SERVICE_TYPE,          .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"mastering_display_metadata",  .default_val.i64 = AV_PKT_DATA_MASTERING_DISPLAY_METADATA,  .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"content_light_level",         .default_val.i64 = AV_PKT_DATA_CONTENT_LIGHT_LEVEL,         .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"icc_profile",                 .default_val.i64 = AV_PKT_DATA_ICC_PROFILE,                 .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
+    {"dynamic_hdr10_plus",          .default_val.i64 = AV_PKT_DATA_DYNAMIC_HDR10_PLUS,          .type = AV_OPT_TYPE_CONST, .flags = A|D, .unit = "side_data_pkt" },
 {NULL},
 };