[FFmpeg-devel] [PATCH 01/13] avcodec/avcodec: add side data to AVCodecContext

[James Almer]

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavcodec/avcodec.c  |  2 ++
 libavcodec/avcodec.h  |  8 +++++
 libavcodec/avpacket.c | 84 +++++++++++++++++++++++++++++++++++++++++++
 libavcodec/packet.h   | 54 ++++++++++++++++++++++++++++
 4 files changed, 148 insertions(+)

diff --git a/libavcodec/avcodec.c b/libavcodec/avcodec.c
index 340abe830e..16869e97f2 100644
--- a/libavcodec/avcodec.c
+++ b/libavcodec/avcodec.c
@@ -467,6 +467,8 @@ av_cold int avcodec_close(AVCodecContext *avctx)
         av_freep(&avctx->internal);
     }
 
+    av_packet_free_side_data_set(&avctx->side_data_set);
+
     for (i = 0; i < avctx->nb_coded_side_data; i++)
         av_freep(&avctx->coded_side_data[i].data);
     av_freep(&avctx->coded_side_data);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index fe41ecc3c9..2902ecf6cb 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -2102,6 +2102,14 @@ typedef struct AVCodecContext {
      *   an error.
      */
     int64_t frame_num;
+
+    /**
+     * Additional data associated with the entire stream.
+     *
+     * - decoding: set by user
+     * - encoding: unused
+     */
+    AVPacketSideDataSet side_data_set;
 } AVCodecContext;
 
 /**
diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index 5fef65e97a..f569731403 100644
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -645,3 +645,87 @@ int ff_side_data_set_prft(AVPacket *pkt, int64_t timestamp)
 
     return 0;
 }
+
+AVPacketSideData *av_packet_get_side_data_from_set(const AVPacketSideDataSet *set,
+                                                   enum AVPacketSideDataType type)
+{
+    for (int i = 0; i < set->nb_side_data; i++)
+        if (set->side_data[i].type == type)
+            return &set->side_data[i];
+
+    return NULL;
+}
+
+static int add_side_data_to_set(AVPacketSideDataSet *set,
+                                AVPacketSideData **psd,
+                                enum AVPacketSideDataType type,
+                                uint8_t *data, size_t size)
+{
+    AVPacketSideData *sd, *tmp;
+
+    for (int i = 0; i < set->nb_side_data; i++) {
+        sd = &set->side_data[i];
+
+        if (sd->type == type) {
+            av_freep(&sd->data);
+            sd->data = data;
+            sd->size = size;
+            *psd = sd;
+            return 0;
+        }
+    }
+
+    if (set->nb_side_data + 1U > FFMIN(INT_MAX, SIZE_MAX / sizeof(*tmp)))
+        return AVERROR(ERANGE);
+
+    tmp = av_realloc_array(set->side_data, set->nb_side_data + 1, sizeof(*tmp));
+    if (!tmp)
+        return AVERROR(ENOMEM);
+
+    set->side_data = tmp;
+    set->nb_side_data++;
+
+    sd = &set->side_data[set->nb_side_data - 1];
+    sd->type = type;
+    sd->data = data;
+    sd->size = size;
+    *psd = sd;
+
+    return 0;
+}
+
+int av_packet_add_side_data_to_set(AVPacketSideDataSet *set,
+                                   enum AVPacketSideDataType type,
+                                   uint8_t *data, size_t size)
+{
+    AVPacketSideData *sd;
+
+    return add_side_data_to_set(set, &sd, type, data, size);
+}
+
+AVPacketSideData *av_packet_new_side_data_to_set(AVPacketSideDataSet *set,
+                                                 enum AVPacketSideDataType type,
+                                                 size_t size)
+{
+    AVPacketSideData *sd = NULL;
+    uint8_t *data = av_malloc(size);
+    int ret;
+
+    if (!data)
+        return NULL;
+
+    ret = add_side_data_to_set(set, &sd, type, data, size);
+    if (ret < 0)
+        av_freep(&data);
+
+    return sd;
+}
+
+void av_packet_free_side_data_set(AVPacketSideDataSet *set)
+{
+    int i;
+    for (i = 0; i < set->nb_side_data; i++)
+        av_freep(&set->side_data[i].data);
+    av_freep(&set->side_data);
+    set->nb_side_data = 0;
+}
diff --git a/libavcodec/packet.h b/libavcodec/packet.h
index f28e7e7011..590c2bf15a 100644
--- a/libavcodec/packet.h
+++ b/libavcodec/packet.h
@@ -318,6 +318,14 @@ typedef struct AVPacketSideData {
     enum AVPacketSideDataType type;
 } AVPacketSideData;
 
+/**
+ * Structure to hold a set of AVPacketSideDataSet
+ */
+typedef struct AVPacketSideDataSet {
+    AVPacketSideData *side_data;
+    int            nb_side_data;
+} AVPacketSideDataSet;
+
 /**
  * This structure stores compressed data. It is typically exported by demuxers
  * and then passed as input to decoders, or received as output from encoders and
@@ -724,6 +732,52 @@ int av_packet_make_writable(AVPacket *pkt);
  */
 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
 
+/**
+ * Allocate a new side data entry into to a set.
+ *
+ * @param set a set to which the side data should be added
+ * @param type side data type
+ * @param size side data size
+ * @return pointer to freshly allocated side data entry or NULL otherwise.
+ */
+AVPacketSideData *av_packet_new_side_data_to_set(AVPacketSideDataSet *set,
+                                                 enum AVPacketSideDataType type,
+                                                 size_t size);
+
+/**
+ * Wrap an existing array as a packet side data into a set.
+ *
+ * @param set a set to which the side data should be added
+ * @param type side information type
+ * @param data the side data array. It must be allocated with the av_malloc()
+ *             family of functions. The ownership of the data is transferred to
+ *             pkt.
+ * @param size side information size
+ * @return a non-negative number on success, a negative AVERROR code on
+ *         failure. On failure, the set is unchanged and the data remains
+ *         owned by the caller.
+ */
+int av_packet_add_side_data_to_set(AVPacketSideDataSet *set,
+                                   enum AVPacketSideDataType type,
+                                   uint8_t *data, size_t size);
+
+/**
+ * Get side information from set.
+ *
+ * @param set a set from which the side data should be fetched
+ * @param type desired side information type
+ * @return pointer to side data if present or NULL otherwise
+ */
+AVPacketSideData *av_packet_get_side_data_from_set(const AVPacketSideDataSet *set,
+                                                   enum AVPacketSideDataType type);
+
+/**
+ * Convenience function to free all the side data stored in a set.
+ *
+ * @param set a set
+ */
+void av_packet_free_side_data_set(AVPacketSideDataSet *set);
+
 /**
  * @}
  */
-- 
2.41.0