+ // See if there's a cached frame for us.
+ if (!frame_finished) {
+ AVPacket pkt;
+ pkt.data = nullptr;
+ pkt.size = 0;
+ if (avcodec_decode_video2(codec_ctx, frame.get(), &frame_finished, &pkt) < 0) {
+ fprintf(stderr, "%s: Cannot decode frame\n", filename.c_str());
+ return nullptr;
+ }
+ }
+ if (!frame_finished) {
+ fprintf(stderr, "%s: Decoder did not output frame.\n", filename.c_str());
+ return nullptr;
+ }
+