Merge commit '4e70d66ded537cadd32dbd02a38c3d86a203c812'

* commit '4e70d66ded537cadd32dbd02a38c3d86a203c812':
  mpegvideo: fix allocation of the hwaccel_picture_private data
  lavc: update the doxy for avcodec_decode_{video,audio} wtih refcounting.

Merged-by: Michael Niedermayer <michaelni@gmx.at>

2 files changed, 28 insertions, 14 deletions

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index df1e247866..c3bd534ed7 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -3628,11 +3628,17 @@ attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *s
  *
  * @param      avctx the codec context
  * @param[out] frame The AVFrame in which to store decoded audio samples.
- *                   Decoders request a buffer of a particular size by setting
- *                   AVFrame.nb_samples prior to calling get_buffer(). The
- *                   decoder may, however, only utilize part of the buffer by
- *                   setting AVFrame.nb_samples to a smaller value in the
- *                   output frame.
+ *                   The decoder will allocate a buffer for the decoded frame by
+ *                   calling the AVCodecContext.get_buffer2() callback.
+ *                   When AVCodecContext.refcounted_frames is set to 1, the frame is
+ *                   reference counted and the returned reference belongs to the
+ *                   caller. The caller must release the frame using av_frame_unref()
+ *                   when the frame is no longer needed. The caller may safely write
+ *                   to the frame if av_frame_is_writable() returns 1.
+ *                   When AVCodecContext.refcounted_frames is set to 0, the returned
+ *                   reference belongs to the decoder and is valid only until the
+ *                   next call to this function or until closing the decoder.
+ *                   The caller may not write to it.
  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
  *                           non-zero.
  * @param[in]  avpkt The input AVPacket containing the input buffer.
@@ -3670,12 +3676,18 @@ int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
  *
  * @param avctx the codec context
  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
- *             Use avcodec_alloc_frame to get an AVFrame, the codec will
- *             allocate memory for the actual bitmap.
- *             with default get/release_buffer(), the decoder frees/reuses the bitmap as it sees fit.
- *             with overridden get/release_buffer() (needs CODEC_CAP_DR1) the user decides into what buffer the decoder
- *                   decodes and the decoder tells the user once it does not need the data anymore,
- *                   the user app can at this point free/reuse/keep the memory as it sees fit.
+ *             Use av_frame_alloc() to get an AVFrame. The codec will
+ *             allocate memory for the actual bitmap by calling the
+ *             AVCodecContext.get_buffer2() callback.
+ *             When AVCodecContext.refcounted_frames is set to 1, the frame is
+ *             reference counted and the returned reference belongs to the
+ *             caller. The caller must release the frame using av_frame_unref()
+ *             when the frame is no longer needed. The caller may safely write
+ *             to the frame if av_frame_is_writable() returns 1.
+ *             When AVCodecContext.refcounted_frames is set to 0, the returned
+ *             reference belongs to the decoder and is valid only until the
+ *             next call to this function or until closing the decoder. The
+ *             caller may not write to it.
  *
  * @param[in] avpkt The input AVpacket containing the input buffer.
  *            You can create such packet with av_init_packet() and by then setting
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index e4fa099acd..4c2ff80c51 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -269,11 +269,12 @@ static int alloc_frame_buffer(MpegEncContext *s, Picture *pic)
     if (s->avctx->hwaccel) {
         assert(!pic->hwaccel_picture_private);
         if (s->avctx->hwaccel->priv_data_size) {
-            pic->hwaccel_picture_private = av_mallocz(s->avctx->hwaccel->priv_data_size);
-            if (!pic->hwaccel_picture_private) {
+            pic->hwaccel_priv_buf = av_buffer_allocz(s->avctx->hwaccel->priv_data_size);
+            if (!pic->hwaccel_priv_buf) {
                 av_log(s->avctx, AV_LOG_ERROR, "alloc_frame_buffer() failed (hwaccel private data allocation)\n");
                 return -1;
             }
+            pic->hwaccel_picture_private = pic->hwaccel_priv_buf->data;
         }
     }
 
@@ -293,7 +294,8 @@ static int alloc_frame_buffer(MpegEncContext *s, Picture *pic)
     if (r < 0 || !pic->f.data[0]) {
         av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (%d %p)\n",
                r, pic->f.data[0]);
-        av_freep(&pic->hwaccel_picture_private);
+        av_buffer_unref(&pic->hwaccel_priv_buf);
+        pic->hwaccel_picture_private = NULL;
         return -1;
     }