From 386c4cb7236650061452026cac365229aa3b0cca Mon Sep 17 00:00:00 2001 From: scheilch Date: Tue, 24 Mar 2026 18:02:00 +0100 Subject: Fix int32 overflow in QSV rate-control parameter computation (#16376) Fix int32 overflow in QSV rate-control parameter computation --- MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs') diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs index 21d4c36f6..9ebaef171 100644 --- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs +++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs @@ -1567,14 +1567,15 @@ namespace MediaBrowser.Controller.MediaEncoding int bitrate = state.OutputVideoBitrate.Value; - // Bit rate under 1000k is not allowed in h264_qsv + // Bit rate under 1000k is not allowed in h264_qsv. if (string.Equals(videoCodec, "h264_qsv", StringComparison.OrdinalIgnoreCase)) { bitrate = Math.Max(bitrate, 1000); } - // Currently use the same buffer size for all encoders - int bufsize = bitrate * 2; + // Currently use the same buffer size for all non-QSV encoders. + // Use long arithmetic to prevent int32 overflow for very high bitrate values. + int bufsize = (int)Math.Min((long)bitrate * 2, int.MaxValue); if (string.Equals(videoCodec, "libsvtav1", StringComparison.OrdinalIgnoreCase)) { @@ -1604,7 +1605,13 @@ namespace MediaBrowser.Controller.MediaEncoding // Set (maxrate == bitrate + 1) to trigger VBR for better bitrate allocation // Set (rc_init_occupancy == 2 * bitrate) and (bufsize == 4 * bitrate) to deal with drastic scene changes - return FormattableString.Invariant($"{mbbrcOpt} -b:v {bitrate} -maxrate {bitrate + 1} -rc_init_occupancy {bitrate * 2} -bufsize {bitrate * 4}"); + // Use long arithmetic and clamp to int.MaxValue to prevent int32 overflow + // (e.g. bitrate * 4 wraps to a negative value for bitrates above ~537 million) + int qsvMaxrate = (int)Math.Min((long)bitrate + 1, int.MaxValue); + int qsvInitOcc = (int)Math.Min((long)bitrate * 2, int.MaxValue); + int qsvBufsize = (int)Math.Min((long)bitrate * 4, int.MaxValue); + + return FormattableString.Invariant($"{mbbrcOpt} -b:v {bitrate} -maxrate {qsvMaxrate} -rc_init_occupancy {qsvInitOcc} -bufsize {qsvBufsize}"); } if (string.Equals(videoCodec, "h264_amf", StringComparison.OrdinalIgnoreCase) -- cgit v1.2.3