vp9_metadata: Avoid allocations and copies of packet structures

[ffmpeg] / libavcodec / cbs.h

diff --git a/libavcodec/cbs.h b/libavcodec/cbs.h
index 967dcd146864327d02158329956f4eb90eb585e8..5260a39c633fc002c284921a43bf25298bf707ba 100644 (file)
--- a/libavcodec/cbs.h
+++ b/libavcodec/cbs.h
@@ -297,7 +297,8 @@ int ff_cbs_write_fragment_data(CodedBitstreamContext *ctx,
 /**
  * Write the bitstream of a fragment to the extradata in codec parameters.
  *
- * This replaces any existing extradata in the structure.
+ * Modifies context and fragment as ff_cbs_write_fragment_data does and
+ * replaces any existing extradata in the structure.
  */
 int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
                            AVCodecParameters *par,
@@ -305,6 +306,13 @@ int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
 
 /**
  * Write the bitstream of a fragment to a packet.
+ *
+ * Modifies context and fragment as ff_cbs_write_fragment_data does.
+ *
+ * On success, the packet's buf is unreferenced and its buf, data and
+ * size fields are set to the corresponding values from the newly updated
+ * fragment; other fields are not touched.  On failure, the packet is not
+ * touched at all.
  */
 int ff_cbs_write_packet(CodedBitstreamContext *ctx,
                         AVPacket *pkt,