lavc: free the output packet when encoding failed or produced no output.

libavcodec/avcodec.h

@@ -3788,6 +3788,10 @@ int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
  *                  avpkt->data is NULL, the encoder will allocate it.
  *                  The encoder will set avpkt->size to the size of the
  *                  output packet.
+ *
+ *                  If this function fails or produces no output, avpkt will be
+ *                  freed using av_free_packet() (i.e. avpkt->destruct will be
+ *                  called to free the user supplied buffer).
  * @param[in] frame AVFrame containing the raw audio data to be encoded.
  *                  May be NULL when flushing an encoder that has the
  *                  CODEC_CAP_DELAY capability set.
@@ -3870,6 +3874,10 @@ int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
  *                  The encoder will set avpkt->size to the size of the
  *                  output packet. The returned data (if any) belongs to the
  *                  caller, he is responsible for freeing it.
+ *
+ *                  If this function fails or produces no output, avpkt will be
+ *                  freed using av_free_packet() (i.e. avpkt->destruct will be
+ *                  called to free the user supplied buffer).
  * @param[in] frame AVFrame containing the raw video data to be encoded.
  *                  May be NULL when flushing an encoder that has the
  *                  CODEC_CAP_DELAY capability set.

libavcodec/utils.c

@@ -864,6 +864,7 @@ int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
     *got_packet_ptr = 0;
 
     if (!(avctx->codec->capabilities & CODEC_CAP_DELAY) && !frame) {
+        av_free_packet(avpkt);
         av_init_packet(avpkt);
         avpkt->size = 0;
         return 0;
@@ -962,6 +963,9 @@ int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
     if (!ret)
         avctx->frame_number++;
 
+    if (ret < 0 || !*got_packet_ptr)
+        av_free_packet(avpkt);
+
     /* NOTE: if we add any audio encoders which output non-keyframe packets,
              this needs to be moved to the encoders, but for now we can do it
              here to simplify things */
@@ -1095,6 +1099,7 @@ int attribute_align_arg avcodec_encode_video2(AVCodecContext *avctx,
     *got_packet_ptr = 0;
 
     if (!(avctx->codec->capabilities & CODEC_CAP_DELAY) && !frame) {
+        av_free_packet(avpkt);
         av_init_packet(avpkt);
         avpkt->size     = 0;
         return 0;
@@ -1121,6 +1126,9 @@ int attribute_align_arg avcodec_encode_video2(AVCodecContext *avctx,
         avctx->frame_number++;
     }
 
+    if (ret < 0 || !*got_packet_ptr)
+        av_free_packet(avpkt);
+
     emms_c();
     return ret;
 }