lavf: add a convenience function for adding side data to a stream

libavformat/internal.h

@@ -366,4 +366,11 @@ static inline int ff_rename(const char *oldpath, const char *newpath)
     return 0;
 }
 
+/**
+ * Add new side data to a stream. If a side data of this type already exists, it
+ * is replaced.
+ */
+uint8_t *ff_stream_new_side_data(AVStream *st, enum AVPacketSideDataType type,
+                                 int size);
+
 #endif /* AVFORMAT_INTERNAL_H */

libavformat/replaygain.c

@@ -33,6 +33,7 @@
 #include "libavutil/replaygain.h"
 
 #include "avformat.h"
+#include "internal.h"
 #include "replaygain.h"
 
 static int32_t parse_value(const char *value, int32_t min)
@@ -69,36 +70,16 @@ static int32_t parse_value(const char *value, int32_t min)
 int ff_replaygain_export_raw(AVStream *st, int32_t tg, uint32_t tp,
                              int32_t ag, uint32_t ap)
 {
-    AVPacketSideData *sd, *tmp;
     AVReplayGain *replaygain;
 
     if (tg == INT32_MIN && ag == INT32_MIN)
         return 0;
 
-    for (int i = 0; i < st->nb_side_data; i++) {
-        AVPacketSideData *src_sd = &st->side_data[i];
-
-        if (src_sd->type == AV_PKT_DATA_REPLAYGAIN)
-            return 0;
-    }
-
-    replaygain = av_mallocz(sizeof(*replaygain));
+    replaygain = (AVReplayGain*)ff_stream_new_side_data(st, AV_PKT_DATA_REPLAYGAIN,
+                                                        sizeof(*replaygain));
     if (!replaygain)
         return AVERROR(ENOMEM);
 
-    tmp = av_realloc_array(st->side_data, st->nb_side_data + 1, sizeof(*tmp));
-    if (!tmp) {
-        av_freep(&replaygain);
-        return AVERROR(ENOMEM);
-    }
-    st->side_data = tmp;
-    st->nb_side_data++;
-
-    sd = &st->side_data[st->nb_side_data - 1];
-    sd->type = AV_PKT_DATA_REPLAYGAIN;
-    sd->data = (uint8_t*)replaygain;
-    sd->size = sizeof(*replaygain);
-
     replaygain->track_gain = tg;
     replaygain->track_peak = tp;
     replaygain->album_gain = ag;

libavformat/utils.c

@@ -3113,3 +3113,40 @@ uint8_t *av_stream_get_side_data(AVStream *st, enum AVPacketSideDataType type,
     }
     return NULL;
 }
+
+uint8_t *ff_stream_new_side_data(AVStream *st, enum AVPacketSideDataType type,
+                                 int size)
+{
+    AVPacketSideData *sd, *tmp;
+    int i;
+    uint8_t *data = av_malloc(size);
+
+    if (!data)
+        return NULL;
+
+    for (i = 0; i < st->nb_side_data; i++) {
+        sd = &st->side_data[i];
+
+        if (sd->type == type) {
+            av_freep(&sd->data);
+            sd->data = data;
+            sd->size = size;
+            return sd->data;
+        }
+    }
+
+    tmp = av_realloc_array(st->side_data, st->nb_side_data + 1, sizeof(*tmp));
+    if (!tmp) {
+        av_freep(&data);
+        return NULL;
+    }
+
+    st->side_data = tmp;
+    st->nb_side_data++;
+
+    sd = &st->side_data[st->nb_side_data - 1];
+    sd->type = type;
+    sd->data = data;
+    sd->size = size;
+    return data;
+}