[FFmpeg-devel] [PATCH] avutil/frame: Add av_frame_transfer_side_data() function

[Anton Khirnov]

From: Soft Works <softworkz at hotmail.com>

Signed-off-by: softworkz <softworkz at hotmail.com>
Signed-off-by: Anton Khirnov <anton at khirnov.net>
---
 doc/APIchanges      |  4 +++
 libavutil/frame.c   | 63 ++++++++++++++++++++++++++-------------------
 libavutil/frame.h   | 20 ++++++++++++++
 libavutil/version.h |  4 +--
 4 files changed, 63 insertions(+), 28 deletions(-)

- renamed the function to av_frame_transfer_side_data(), since actually
  copying side data is only one of the two possible modes of behavior
  (and not even the default one)
- renamed flags accordingly
- added the AV_FRAME_TRANSFER_SD_FILTER flags as discussed

diff --git a/doc/APIchanges b/doc/APIchanges
index 2914ad6734..79cfea00b8 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -14,6 +14,10 @@ libavutil:     2021-04-27
 
 API changes, most recent first:
 
+2021-12-02 - xxxxxxxxxx - lavu 57.11.100 - frame.h
+  Add av_frame_transfer_side_data(), AV_FRAME_TRANSFER_SD_COPY, and
+  AV_FRAME_TRANSFER_SD_FILTER.
+
 2021-11-xx - xxxxxxxxxx - lavfi 8.19.100 - avfilter.h
   Add AVFILTER_FLAG_METADATA_ONLY.
 
diff --git a/libavutil/frame.c b/libavutil/frame.c
index 0912ad9131..0b087cc4c9 100644
--- a/libavutil/frame.c
+++ b/libavutil/frame.c
@@ -253,9 +253,40 @@ int av_frame_get_buffer(AVFrame *frame, int align)
     return AVERROR(EINVAL);
 }
 
+int av_frame_transfer_side_data(AVFrame *dst, const AVFrame *src, int flags)
+{
+    for (unsigned i = 0; i < src->nb_side_data; i++) {
+        const AVFrameSideData *sd_src = src->side_data[i];
+        AVFrameSideData *sd_dst;
+        if ((flags & AV_FRAME_TRANSFER_SD_FILTER) &&
+            sd_src->type == AV_FRAME_DATA_PANSCAN          &&
+            (src->width != dst->width || src->height != dst->height))
+            continue;
+        if (flags & AV_FRAME_TRANSFER_SD_COPY) {
+            sd_dst = av_frame_new_side_data(dst, sd_src->type,
+                                            sd_src->size);
+            if (!sd_dst) {
+                wipe_side_data(dst);
+                return AVERROR(ENOMEM);
+            }
+            memcpy(sd_dst->data, sd_src->data, sd_src->size);
+        } else {
+            AVBufferRef *ref = av_buffer_ref(sd_src->buf);
+            sd_dst = av_frame_new_side_data_from_buf(dst, sd_src->type, ref);
+            if (!sd_dst) {
+                av_buffer_unref(&ref);
+                wipe_side_data(dst);
+                return AVERROR(ENOMEM);
+            }
+        }
+        av_dict_copy(&sd_dst->metadata, sd_src->metadata, 0);
+    }
+    return 0;
+}
+
 static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
 {
-    int ret, i;
+    int ret;
 
     dst->key_frame              = src->key_frame;
     dst->pict_type              = src->pict_type;
@@ -291,31 +322,11 @@ static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
 
     av_dict_copy(&dst->metadata, src->metadata, 0);
 
-    for (i = 0; i < src->nb_side_data; i++) {
-        const AVFrameSideData *sd_src = src->side_data[i];
-        AVFrameSideData *sd_dst;
-        if (   sd_src->type == AV_FRAME_DATA_PANSCAN
-            && (src->width != dst->width || src->height != dst->height))
-            continue;
-        if (force_copy) {
-            sd_dst = av_frame_new_side_data(dst, sd_src->type,
-                                            sd_src->size);
-            if (!sd_dst) {
-                wipe_side_data(dst);
-                return AVERROR(ENOMEM);
-            }
-            memcpy(sd_dst->data, sd_src->data, sd_src->size);
-        } else {
-            AVBufferRef *ref = av_buffer_ref(sd_src->buf);
-            sd_dst = av_frame_new_side_data_from_buf(dst, sd_src->type, ref);
-            if (!sd_dst) {
-                av_buffer_unref(&ref);
-                wipe_side_data(dst);
-                return AVERROR(ENOMEM);
-            }
-        }
-        av_dict_copy(&sd_dst->metadata, sd_src->metadata, 0);
-    }
+    ret = av_frame_transfer_side_data(dst, src,
+            (force_copy ? AV_FRAME_TRANSFER_SD_COPY : 0) |
+            AV_FRAME_TRANSFER_SD_FILTER);
+    if (ret < 0)
+        return ret;
 
     ret = av_buffer_replace(&dst->opaque_ref, src->opaque_ref);
     ret |= av_buffer_replace(&dst->private_ref, src->private_ref);
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 3f295f6b9e..deb399f1da 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -873,6 +873,26 @@ AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
  */
 void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
 
+/**
+ * Copy side data, rather than creating new references.
+ */
+#define AV_FRAME_TRANSFER_SD_COPY      (1 << 0)
+/**
+ * Filter out side data that does not match dst properties.
+ */
+#define AV_FRAME_TRANSFER_SD_FILTER    (1 << 1)
+
+/**
+ * Transfer all side-data from src to dst.
+ *
+ * @param flags a combination of AV_FRAME_TRANSFER_SD_*
+ *
+ * @return >= 0 on success, a negative AVERROR on error.
+ *
+ * @note This function will create new references to side data buffers in src,
+ * unless the AV_FRAME_TRANSFER_SD_COPY flag is passed.
+ */
+int av_frame_transfer_side_data(AVFrame *dst, const AVFrame *src, int flags);
 
 /**
  * Flags for frame cropping.
diff --git a/libavutil/version.h b/libavutil/version.h
index 017fc277a6..0e7b36865a 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -79,8 +79,8 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  57
-#define LIBAVUTIL_VERSION_MINOR  10
-#define LIBAVUTIL_VERSION_MICRO 101
+#define LIBAVUTIL_VERSION_MINOR  11
+#define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \
-- 
2.33.0