Move the new avcodec implementation before the old

The API to decode the video frames is different depending on the
libavcodec version.

Move the new API usage to the #if-block.

app/src/decoder.c

@@ -94,7 +94,19 @@ static int run_decoder(void *data) {
     while (!av_read_frame(format_ctx, &packet) && !avio_ctx->eof_reached) {
 // the new decoding/encoding API has been introduced by:
 // <http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=7fc329e2dd6226dfecaa4a1d7adf353bf2773726>
-#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57, 37, 0)
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 37, 0)
+        int ret;
+        if ((ret = avcodec_send_packet(codec_ctx, &packet)) < 0) {
+            LOGE("Could not send video packet: %d", ret);
+            goto run_quit;
+        }
+        if ((ret = avcodec_receive_frame(codec_ctx, decoder->frames->decoding_frame)) < 0) {
+            LOGE("Could not receive video frame: %d", ret);
+            goto run_quit;
+        }
+
+        push_frame(decoder);
+#else
         while (packet.size > 0) {
             int got_picture;
             int len = avcodec_decode_video2(codec_ctx, decoder->frames->decoding_frame, &got_picture, &packet);
@@ -108,18 +120,6 @@ static int run_decoder(void *data) {
             packet.size -= len;
             packet.data += len;
         }
-#else
-        int ret;
-        if ((ret = avcodec_send_packet(codec_ctx, &packet)) < 0) {
-            LOGE("Could not send video packet: %d", ret);
-            goto run_quit;
-        }
-        if ((ret = avcodec_receive_frame(codec_ctx, decoder->frames->decoding_frame)) < 0) {
-            LOGE("Could not receive video frame: %d", ret);
-            goto run_quit;
-        }
-
-        push_frame(decoder);
 #endif
     }