unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
codec_ctx, avcodec_close);
- // Read packets until we have a frame.
+ // Read packets until we have a frame or there are none left.
int frame_finished = 0;
auto frame = av_frame_alloc_unique();
do {
pkt.data = nullptr;
pkt.size = 0;
if (av_read_frame(format_ctx.get(), &pkt) < 0) {
- fprintf(stderr, "%s: Cannot read frame\n", filename.c_str());
- return nullptr;
+ break;
}
if (pkt.stream_index != stream_index) {
continue;
}
} while (!frame_finished);
+ // 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;
+ }
+
// TODO: Scale down if needed!
uint8_t *pic_data[4] = {nullptr};
unique_ptr<uint8_t *, decltype(av_freep)*> pic_data_cleanup(