doc/examples/filtering_audio: switch to new decoding API

doc/examples/filtering_audio.c

@@ -216,10 +216,9 @@ static void print_frame(const AVFrame *frame)
 int main(int argc, char **argv)
 {
     int ret;
-    AVPacket packet0, packet;
+    AVPacket packet;
     AVFrame *frame = av_frame_alloc();
     AVFrame *filt_frame = av_frame_alloc();
-    int got_frame;
 
     if (!frame || !filt_frame) {
         perror("Could not allocate frame");
@@ -239,28 +238,29 @@ int main(int argc, char **argv)
         goto end;
 
     /* read all packets */
-    packet0.data = NULL;
-    packet.data = NULL;
     while (1) {
-        if (!packet0.data) {
         if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
             break;
-            packet0 = packet;
-        }
 
         if (packet.stream_index == audio_stream_index) {
-            got_frame = 0;
-            ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, &packet);
+            ret = avcodec_send_packet(dec_ctx, &packet);
             if (ret < 0) {
-                av_log(NULL, AV_LOG_ERROR, "Error decoding audio\n");
-                continue;
+                av_log(NULL, AV_LOG_ERROR, "Error while sending a packet to the decoder\n");
+                break;
+            }
+
+            while (ret >= 0) {
+                ret = avcodec_receive_frame(dec_ctx, frame);
+                if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
+                    break;
+                } else if (ret < 0) {
+                    av_log(NULL, AV_LOG_ERROR, "Error while receiving a frame from the decoder\n");
+                    goto end;
                 }
-            packet.size -= ret;
-            packet.data += ret;
 
-            if (got_frame) {
+                if (ret >= 0) {
                     /* push the audio data from decoded frame into the filtergraph */
-                if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, 0) < 0) {
+                    if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) {
                         av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");
                         break;
                     }
@@ -275,14 +275,11 @@ int main(int argc, char **argv)
                         print_frame(filt_frame);
                         av_frame_unref(filt_frame);
                     }
+                    av_frame_unref(frame);
+                }
             }
-
-            if (packet.size <= 0)
-                av_packet_unref(&packet0);
-        } else {
-            /* discard non-wanted packets */
-            av_packet_unref(&packet0);
         }
+        av_packet_unref(&packet);
     }
 end:
     avfilter_graph_free(&filter_graph);