Add TORCH_CHECK for stream type

Author: NicolasHug

src/torchcodec/decoders/_core/VideoDecoder.cpp

@@ -869,6 +869,7 @@ VideoDecoder::DecodedOutput VideoDecoder::convertAVFrameToDecodedOutput(
   AVFrame* frame = rawOutput.frame.get();
   output.streamIndex = streamIndex;
   auto& streamInfo = streams_[streamIndex];
+  TORCH_CHECK(streamInfo.stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO);
   output.pts = frame->pts;
   output.ptsSeconds =
       ptsToSeconds(frame->pts, formatContext_->streams[streamIndex]->time_base);