--- a/torchvision/csrc/io/decoder/video_stream.cpp	2025-09-29 09:28:57.678370404 -0400
+++ b/torchvision/csrc/io/decoder/video_stream.cpp	2025-09-29 09:29:51.544541164 -0400
@@ -122,7 +122,7 @@ int VideoStream::copyFrameBytes(ByteStor
 void VideoStream::setHeader(DecoderHeader* header, bool flush) {
   Stream::setHeader(header, flush);
   if (!flush) { // no frames for video flush
-    header->keyFrame = frame_->key_frame;
+    header->keyFrame = !!(frame_->flags & AV_FRAME_FLAG_KEY);
     header->fps = av_q2d(av_guess_frame_rate(
         inputCtx_, inputCtx_->streams[format_.stream], nullptr));
   }