introduce side information for AVPacket

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/avcodec.h

@@ -1035,6 +1035,10 @@ typedef struct AVPanScan{
 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
 
+enum AVPacketSideDataType {
+    AV_PKT_DATA_PALETTE,
+};
+
 typedef struct AVPacket {
     /**
      * Presentation timestamp in AVStream->time_base units; the time at which
@@ -1056,6 +1060,17 @@ typedef struct AVPacket {
     int   size;
     int   stream_index;
     int   flags;
+    /**
+     * Additional packet data that can be provided by the container.
+     * Packet can contain several types of side information.
+     */
+    struct {
+        uint8_t *data;
+        int      size;
+        enum AVPacketSideDataType type;
+    } *side_data;
+    int side_data_elems;
+
     /**
      * Duration of this packet in AVStream->time_base units, 0 if unknown.
      * Equals next_pts - this_pts in presentation order.
@@ -3202,6 +3217,28 @@ int av_dup_packet(AVPacket *pkt);
  */
 void av_free_packet(AVPacket *pkt);
 
+/**
+ * Allocate new information of a packet.
+ *
+ * @param pkt packet
+ * @param type side information type
+ * @param size side information size
+ * @return pointer to fresh allocated data or NULL otherwise
+ */
+uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int size);
+
+/**
+ * Get side information from packet.
+ *
+ * @param pkt packet
+ * @param type desired side information type
+ * @param size pointer for side information size to store (optional)
+ * @return pointer to data if present or NULL otherwise
+ */
+uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int *size);
+
 /* resample.c */
 
 struct ReSampleContext;

libavcodec/avpacket.c

@@ -26,12 +26,21 @@
 void av_destruct_packet_nofree(AVPacket *pkt)
 {
     pkt->data = NULL; pkt->size = 0;
+    pkt->side_data       = NULL;
+    pkt->side_data_elems = 0;
 }
 
 void av_destruct_packet(AVPacket *pkt)
 {
+    int i;
+
     av_free(pkt->data);
     pkt->data = NULL; pkt->size = 0;
+
+    for (i = 0; i < pkt->side_data_elems; i++)
+        av_free(pkt->side_data[i].data);
+    av_freep(&pkt->side_data);
+    pkt->side_data_elems = 0;
 }
 
 void av_init_packet(AVPacket *pkt)
@@ -44,6 +53,8 @@ void av_init_packet(AVPacket *pkt)
     pkt->flags = 0;
     pkt->stream_index = 0;
     pkt->destruct= NULL;
+    pkt->side_data       = NULL;
+    pkt->side_data_elems = 0;
 }
 
 int av_new_packet(AVPacket *pkt, int size)
@@ -89,21 +100,38 @@ int av_grow_packet(AVPacket *pkt, int grow_by)
     return 0;
 }
 
+#define DUP_DATA(dst, size, padding) \
+    do { \
+        void *data; \
+        if (padding) { \
+            if ((unsigned)(size) > (unsigned)(size) + FF_INPUT_BUFFER_PADDING_SIZE) \
+                return AVERROR(ENOMEM); \
+            data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE); \
+        } else { \
+            data = av_malloc(size); \
+        } \
+        if (!data) \
+            return AVERROR(ENOMEM); \
+        memcpy(data, dst, size); \
+        if (padding) \
+            memset((uint8_t*)data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE); \
+        dst = data; \
+    } while(0)
+
 int av_dup_packet(AVPacket *pkt)
 {
     if (((pkt->destruct == av_destruct_packet_nofree) || (pkt->destruct == NULL)) && pkt->data) {
-        uint8_t *data;
-        /* We duplicate the packet and don't forget to add the padding again. */
-        if((unsigned)pkt->size > (unsigned)pkt->size + FF_INPUT_BUFFER_PADDING_SIZE)
-            return AVERROR(ENOMEM);
-        data = av_malloc(pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!data) {
-            return AVERROR(ENOMEM);
-        }
-        memcpy(data, pkt->data, pkt->size);
-        memset(data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
-        pkt->data = data;
+        DUP_DATA(pkt->data, pkt->size, 1);
         pkt->destruct = av_destruct_packet;
+
+        if (pkt->side_data_elems) {
+            int i;
+
+            DUP_DATA(pkt->side_data, pkt->side_data_elems * sizeof(*pkt->side_data), 0);
+            for (i = 0; i < pkt->side_data_elems; i++) {
+                DUP_DATA(pkt->side_data[i].data, pkt->side_data[i].size, 1);
+            }
+        }
     }
     return 0;
 }
@@ -113,5 +141,46 @@ void av_free_packet(AVPacket *pkt)
     if (pkt) {
         if (pkt->destruct) pkt->destruct(pkt);
         pkt->data = NULL; pkt->size = 0;
+        pkt->side_data       = NULL;
+        pkt->side_data_elems = 0;
+    }
+}
+
+uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int size)
+{
+    int elems = pkt->side_data_elems;
+
+    if ((unsigned)elems + 1 > INT_MAX / sizeof(*pkt->side_data))
+        return NULL;
+    if ((unsigned)size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
+        return NULL;
+
+    pkt->side_data = av_realloc(pkt->side_data, (elems + 1) * sizeof(*pkt->side_data));
+    if (!pkt->side_data)
+        return NULL;
+
+    pkt->side_data[elems].data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!pkt->side_data[elems].data)
+        return NULL;
+    pkt->side_data[elems].size = size;
+    pkt->side_data[elems].type = type;
+    pkt->side_data_elems++;
+
+    return pkt->side_data[elems].data;
+}
+
+uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int *size)
+{
+    int i;
+
+    for (i = 0; i < pkt->side_data_elems; i++) {
+        if (pkt->side_data[i].type == type) {
+            if (size)
+                *size = pkt->side_data[i].size;
+            return pkt->side_data[i].data;
+        }
     }
+    return NULL;
 }

libavcodec/version.h

@@ -21,8 +21,8 @@
 #define AVCODEC_VERSION_H
 
 #define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 119
-#define LIBAVCODEC_VERSION_MICRO  1
+#define LIBAVCODEC_VERSION_MINOR 120
+#define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \