avpacket: Replace av_free_packet with av_packet_unref

`av_packet_unref` matches the AVFrame ref-counted API and can be used as
a drop in replacement.

Deprecate `av_free_packet`.

avconv.c

@@ -270,7 +270,7 @@ static void write_frame(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
      */
     if (!(avctx->codec_type == AVMEDIA_TYPE_VIDEO && avctx->codec)) {
         if (ost->frame_number >= ost->max_frames) {
-            av_free_packet(pkt);
+            av_packet_unref(pkt);
             return;
         }
         ost->frame_number++;
@@ -288,7 +288,7 @@ static void write_frame(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
                                            pkt->data, pkt->size,
                                            pkt->flags & AV_PKT_FLAG_KEY);
         if (a > 0) {
-            av_free_packet(pkt);
+            av_packet_unref(pkt);
             new_pkt.buf = av_buffer_create(new_pkt.data, new_pkt.size,
                                            av_buffer_default_free, NULL, 0);
             if (!new_pkt.buf)
@@ -2158,7 +2158,7 @@ static void free_input_threads(void)
         pthread_mutex_lock(&f->fifo_lock);
         while (av_fifo_size(f->fifo)) {
             av_fifo_generic_read(f->fifo, &pkt, sizeof(pkt), NULL);
-            av_free_packet(&pkt);
+            av_packet_unref(&pkt);
         }
         pthread_cond_signal(&f->fifo_cond);
         pthread_mutex_unlock(&f->fifo_lock);
@@ -2168,7 +2168,7 @@ static void free_input_threads(void)
 
         while (av_fifo_size(f->fifo)) {
             av_fifo_generic_read(f->fifo, &pkt, sizeof(pkt), NULL);
-            av_free_packet(&pkt);
+            av_packet_unref(&pkt);
         }
         av_fifo_free(f->fifo);
     }
@@ -2483,7 +2483,7 @@ static int process_input(void)
     process_input_packet(ist, &pkt, 0);
 
 discard_packet:
-    av_free_packet(&pkt);
+    av_packet_unref(&pkt);
 
     return 0;
 }

avplay.c

@@ -299,7 +299,7 @@ static void packet_queue_flush(PacketQueue *q)
     SDL_LockMutex(q->mutex);
     for (pkt = q->first_pkt; pkt != NULL; pkt = pkt1) {
         pkt1 = pkt->next;
-        av_free_packet(&pkt->pkt);
+        av_packet_unref(&pkt->pkt);
         av_freep(&pkt);
     }
     q->last_pkt = NULL;
@@ -1617,7 +1617,7 @@ static int video_thread(void *arg)
         while (is->paused && !is->videoq.abort_request)
             SDL_Delay(10);
 
-        av_free_packet(&pkt);
+        av_packet_unref(&pkt);
 
         ret = get_video_frame(is, frame, &pts_int, &pkt);
         if (ret < 0)
@@ -1684,7 +1684,7 @@ static int video_thread(void *arg)
     av_freep(&vfilters);
     avfilter_graph_free(&graph);
 #endif
-    av_free_packet(&pkt);
+    av_packet_unref(&pkt);
     av_frame_free(&frame);
     return 0;
 }
@@ -1753,7 +1753,7 @@ static int subtitle_thread(void *arg)
             is->subpq_size++;
             SDL_UnlockMutex(is->subpq_mutex);
         }
-        av_free_packet(pkt);
+        av_packet_unref(pkt);
     }
     return 0;
 }
@@ -1984,7 +1984,7 @@ static int audio_decode_frame(VideoState *is, double *pts_ptr)
 
         /* free the current packet */
         if (pkt->data)
-            av_free_packet(pkt);
+            av_packet_unref(pkt);
         memset(pkt_temp, 0, sizeof(*pkt_temp));
 
         if (is->paused || is->audioq.abort_request) {
@@ -2181,7 +2181,7 @@ static void stream_component_close(VideoState *is, int stream_index)
         SDL_CloseAudio();
 
         packet_queue_end(&is->audioq);
-        av_free_packet(&is->audio_pkt);
+        av_packet_unref(&is->audio_pkt);
         if (is->avr)
             avresample_free(&is->avr);
         av_freep(&is->audio_buf1);
@@ -2490,7 +2490,7 @@ static int decode_thread(void *arg)
         } else if (pkt->stream_index == is->subtitle_stream && pkt_in_play_range) {
             packet_queue_put(&is->subtitleq, pkt);
         } else {
-            av_free_packet(pkt);
+            av_packet_unref(pkt);
         }
     }
     /* wait until the end */

doc/APIchanges

@@ -13,6 +13,10 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2015-xx-xx - xxxxxxx - lavc 57.7.0 - avcodec.h
+  Deprecate av_free_packet(). Use av_packet_unref() as replacement,
+  it resets the packet in a more consistent way.
+
 2015-xx-xx - xxxxxxx - lavc 57.5.0 - avcodec.h
   Add data and linesize array to AVSubtitleRect, to be used instead of
   the ones from the embedded AVPicture.

doc/examples/avcodec.c

@@ -206,7 +206,7 @@ static void audio_encode_example(const char *filename)
         }
         if (got_output) {
             fwrite(pkt.data, 1, pkt.size, f);
-            av_free_packet(&pkt);
+            av_packet_unref(&pkt);
         }
     }
     fclose(f);
@@ -403,7 +403,7 @@ static void video_encode_example(const char *filename)
         if (got_output) {
             printf("encoding frame %3d (size=%5d)\n", i, pkt.size);
             fwrite(pkt.data, 1, pkt.size, f);
-            av_free_packet(&pkt);
+            av_packet_unref(&pkt);
         }
     }
 
@@ -420,7 +420,7 @@ static void video_encode_example(const char *filename)
         if (got_output) {
             printf("encoding frame %3d (size=%5d)\n", i, pkt.size);
             fwrite(pkt.data, 1, pkt.size, f);
-            av_free_packet(&pkt);
+            av_packet_unref(&pkt);
         }
     }
 

doc/examples/transcode_aac.c

@@ -337,7 +337,7 @@ static int decode_audio_frame(AVFrame *frame,
                                        data_present, &input_packet)) < 0) {
         fprintf(stderr, "Could not decode frame (error '%s')\n",
                 get_error_text(error));
-        av_free_packet(&input_packet);
+        av_packet_unref(&input_packet);
         return error;
     }
 
@@ -347,7 +347,7 @@ static int decode_audio_frame(AVFrame *frame,
      */
     if (*finished && *data_present)
         *finished = 0;
-    av_free_packet(&input_packet);
+    av_packet_unref(&input_packet);
     return 0;
 }
 
@@ -585,7 +585,7 @@ static int encode_audio_frame(AVFrame *frame,
                                        frame, data_present)) < 0) {
         fprintf(stderr, "Could not encode frame (error '%s')\n",
                 get_error_text(error));
-        av_free_packet(&output_packet);
+        av_packet_unref(&output_packet);
         return error;
     }
 
@@ -594,11 +594,11 @@ static int encode_audio_frame(AVFrame *frame,
         if ((error = av_write_frame(output_format_context, &output_packet)) < 0) {
             fprintf(stderr, "Could not write frame (error '%s')\n",
                     get_error_text(error));
-            av_free_packet(&output_packet);
+            av_packet_unref(&output_packet);
             return error;
         }
 
-        av_free_packet(&output_packet);
+        av_packet_unref(&output_packet);
     }
 
     return 0;

libavcodec/avcodec.h

@@ -1151,15 +1151,19 @@ typedef struct AVPacketSideData {
  * ABI. Thus it may be allocated on stack and no new fields can be added to it
  * without libavcodec and libavformat major bump.
  *
- * The semantics of data ownership depends on the buf or destruct (deprecated)
- * fields. If either is set, the packet data is dynamically allocated and is
- * valid indefinitely until av_free_packet() is called (which in turn calls
- * av_buffer_unref()/the destruct callback to free the data). If neither is set,
- * the packet data is typically backed by some static buffer somewhere and is
- * only valid for a limited time (e.g. until the next read call when demuxing).
+ * The semantics of data ownership depends on the buf field.
+ * If it is set, the packet data is dynamically allocated and is
+ * valid indefinitely until a call to av_packet_unref() reduces the
+ * reference count to 0.
  *
- * The side data is always allocated with av_malloc() and is freed in
- * av_free_packet().
+ * If the buf field is not set av_packet_ref() would make a copy instead
+ * of increasing the reference count.
+ *
+ * The side data is always allocated with av_malloc(), copied by
+ * av_packet_ref() and freed by av_packet_unref().
+ *
+ * @see av_packet_ref
+ * @see av_packet_unref
  */
 typedef struct AVPacket {
     /**
@@ -3477,14 +3481,17 @@ int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
  * packet is allocated if it was not really allocated.
  */
 int av_dup_packet(AVPacket *pkt);
-
+#if FF_API_AVPACKET_OLD_API
 /**
  * Free a packet.
  *
+ * @deprecated Use av_packet_unref
+ *
  * @param pkt packet to free
  */
+attribute_deprecated
 void av_free_packet(AVPacket *pkt);
-
+#endif
 /**
  * Allocate new information of a packet.
  *
@@ -4070,8 +4077,7 @@ AVCodec *avcodec_find_encoder_by_name(const char *name);
  *                  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).
+ *                  freed using av_packet_unref().
  * @param[in] frame AVFrame containing the raw audio data to be encoded.
  *                  May be NULL when flushing an encoder that has the
  *                  AV_CODEC_CAP_DELAY capability set.
@@ -4112,8 +4118,7 @@ int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
  *                  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).
+ *                  freed using av_packet_unref().
  * @param[in] frame AVFrame containing the raw video data to be encoded.
  *                  May be NULL when flushing an encoder that has the
  *                  AV_CODEC_CAP_DELAY capability set.

libavcodec/avpacket.c

@@ -184,7 +184,7 @@ int av_dup_packet(AVPacket *pkt)
     return 0;
 
 failed_alloc:
-    av_free_packet(pkt);
+    av_packet_unref(pkt);
     return AVERROR(ENOMEM);
 }
 
@@ -197,6 +197,8 @@ void av_packet_free_side_data(AVPacket *pkt)
     pkt->side_data_elems = 0;
 }
 
+#if FF_API_AVPACKET_OLD_API
+FF_DISABLE_DEPRECATION_WARNINGS
 void av_free_packet(AVPacket *pkt)
 {
     if (pkt) {
@@ -208,6 +210,8 @@ void av_free_packet(AVPacket *pkt)
         av_packet_free_side_data(pkt);
     }
 }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
 uint8_t *av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                  int size)

libavcodec/jpeglsenc.c

@@ -406,7 +406,7 @@ static int encode_picture_ls(AVCodecContext *avctx, AVPacket *pkt,
     return 0;
 
 memfail:
-    av_free_packet(pkt);
+    av_packet_unref(pkt);
     av_freep(&buf2);
     av_freep(&state);
     av_freep(&zero);

libavcodec/libxvid.c

@@ -811,7 +811,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
         return 0;
     } else {
         if (!user_packet)
-            av_free_packet(pkt);
+            av_packet_unref(pkt);
         if (!xerr)
             return 0;
         av_log(avctx, AV_LOG_ERROR,

libavcodec/mpegvideo_enc.c

@@ -1146,7 +1146,7 @@ static int encode_frame(AVCodecContext *c, AVFrame *frame)
         return ret;
 
     ret = pkt.size;
-    av_free_packet(&pkt);
+    av_packet_unref(&pkt);
     return ret;
 }