[FFmpeg-devel] [PATCH 01/10] avcodec/packet: add side data set struct and helpers

[James Almer]

This will be useful in the following commits.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavcodec/avpacket.c | 99 +++++++++++++++++++++++++++++++++++++++++++
 libavcodec/packet.h   | 74 ++++++++++++++++++++++++++++++++
 2 files changed, 173 insertions(+)

diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index 5fef65e97a..5b133c5d8a 100644
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -645,3 +645,102 @@ int ff_side_data_set_prft(AVPacket *pkt, int64_t timestamp)
 
     return 0;
 }
+
+AVPacketSideData *av_packet_side_data_set_get(const AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type)
+{
+    for (int i = 0; i < set->nb_sd; i++)
+        if (set->sd[i]->type == type)
+            return set->sd[i];
+
+    return NULL;
+}
+
+static AVPacketSideData *add_side_data_to_set(AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type,
+                                              uint8_t *data, size_t size)
+{
+    AVPacketSideData *sd, **tmp;
+
+    for (int i = 0; i < set->nb_sd; i++) {
+        sd = set->sd[i];
+        if (sd->type != type)
+            continue;
+
+        av_freep(&sd->data);
+        sd->data = data;
+        sd->size = size;
+        return sd;
+    }
+
+    if (set->nb_sd + 1U > INT_MAX)
+        return NULL;
+
+    tmp = av_realloc_array(set->sd, set->nb_sd + 1, sizeof(*tmp));
+    if (!tmp)
+        return NULL;
+
+    set->sd = tmp;
+
+    sd = av_mallocz(sizeof(*sd));
+    if (!sd)
+        return NULL;
+
+    sd->type = type;
+    sd->data = data;
+    sd->size = size;
+
+    set->sd[set->nb_sd++] = sd;
+
+    return sd;
+}
+
+AVPacketSideData *av_packet_side_data_set_add(AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type,
+                                              uint8_t *data, size_t size,
+                                              int flags)
+{
+    return add_side_data_to_set(set, type, data, size);
+}
+
+AVPacketSideData *av_packet_side_data_set_new(AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type,
+                                              size_t size, int flags)
+{
+    AVPacketSideData *sd = NULL;
+    uint8_t *data = av_malloc(size);
+
+    if (!data)
+        return NULL;
+
+    sd = add_side_data_to_set(set, type, data, size);
+    if (!sd)
+        av_freep(&data);
+
+    return sd;
+}
+
+void av_packet_side_data_set_remove(AVPacketSideDataSet *set,
+                                    enum AVPacketSideDataType type)
+{
+    for (int i = set->nb_sd - 1; i >= 0; i--) {
+        AVPacketSideData *sd = set->sd[i];
+        if (sd->type != type)
+            continue;
+        av_free(set->sd[i]->data);
+        av_free(set->sd[i]);
+        set->sd[i] = set->sd[--set->nb_sd];
+        break;
+    }
+}
+
+void av_packet_side_data_set_free(AVPacketSideDataSet *set)
+{
+    for (int i = 0; i < set->nb_sd; i++) {
+        av_free(set->sd[i]->data);
+        av_free(set->sd[i]);
+    }
+    set->nb_sd = 0;
+
+    av_freep(&set->sd);
+}
diff --git a/libavcodec/packet.h b/libavcodec/packet.h
index f28e7e7011..87720ab909 100644
--- a/libavcodec/packet.h
+++ b/libavcodec/packet.h
@@ -318,6 +318,20 @@ typedef struct AVPacketSideData {
     enum AVPacketSideDataType type;
 } AVPacketSideData;
 
+/**
+ * Structure to hold a set of AVPacketSideData
+ *
+ * @see av_packet_side_data_set_new
+ * @see av_packet_side_data_set_add
+ * @see av_packet_side_data_set_get
+ * @see av_packet_side_data_set_remove
+ * @see av_packet_side_data_set_free
+ */
+typedef struct AVPacketSideDataSet {
+    AVPacketSideData **sd;
+    int             nb_sd;
+} 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 +738,66 @@ 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
+ * @param flags currently unused
+ * @return pointer to freshly allocated side data entry on success, or NULL
+ *         otherwise.
+ */
+AVPacketSideData *av_packet_side_data_set_new(AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type,
+                                              size_t size, int flags);
+
+/**
+ * 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 data type
+ * @param data a data array. It must be allocated with the av_malloc() family
+ *             of functions. The ownership of the data is transferred to the
+ *             set on success
+ * @param size size of the data array
+ * @param flags currently unused
+ * @return pointer to freshly allocated side data entry on success, or NULL
+ *         otherwise. On failure, the set is unchanged and the data remains
+ *         owned by the caller.
+ */
+AVPacketSideData *av_packet_side_data_set_add(AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type,
+                                              uint8_t *data, size_t size,
+                                              int flags);
+
+/**
+ * Remove side data of the given type from a set.
+ *
+ * @param set a set from which the side data should be removed
+ * @param type side information type
+ */
+void av_packet_side_data_set_remove(AVPacketSideDataSet *set,
+                                    enum AVPacketSideDataType type);
+
+/**
+ * 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_side_data_set_get(const AVPacketSideDataSet *set,
+                                              enum AVPacketSideDataType type);
+
+/**
+ * Convenience function to free all the side data stored in a set.
+ *
+ * @param set the set to free
+ */
+void av_packet_side_data_set_free(AVPacketSideDataSet *set);
+
 /**
  * @}
  */
-- 
2.42.0