From 1eeee68d8eb678665730bdd7862598be15867028 Mon Sep 17 00:00:00 2001 From: Connor Worley Date: Mon, 29 Jan 2024 22:26:26 -0800 Subject: lavc/dxv: fix incorrect back-reference index calculation in DXT5 decoding This bug causes the DXT5 decoder to produce incorrect block texture data. After the fix, textures are visually correct and match data decoded by Resolume Alley (extracted with Nvida Nsight for comparison). Current FATE DXT5 samples did not cover this case. Signed-off-by: Connor Worley --- libavcodec/dxv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/dxv.c b/libavcodec/dxv.c index 1e6791e63f..e1c7cee3e8 100644 --- a/libavcodec/dxv.c +++ b/libavcodec/dxv.c @@ -955,7 +955,7 @@ static int dxv_decompress_dxt5(AVCodecContext *avctx) break; case 2: /* Copy two dwords from a previous index */ - idx = 8 + bytestream2_get_le16(gbc); + idx = 8 + 4 * bytestream2_get_le16(gbc); if (idx > pos || (unsigned int)(pos - idx) + 2 > ctx->tex_size / 4) return AVERROR_INVALIDDATA; prev = AV_RL32(ctx->tex_data + 4 * (pos - idx)); -- cgit v1.2.3