| Message ID | 20240202003400.30850-2-connorbworley@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/2] lavc/texturedsp: fix premult2straight inversion | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/commit_msg_loongarch64 | warning | Please wrap lines in the body of the commit message between 60 and 72 characters. |
| andriy/commit_msg_x86 | warning | Please wrap lines in the body of the commit message between 60 and 72 characters. |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | fail | Make fate failed |
Attached is a comparison of the input and decoding with DXT4 and DXT5. DXT5 produces dark outlines that are not present in the input. Also, I have a prototype "Normal Quality, With Alpha" encoder that produces nasty results in Resolume unless alpha is premultiplied. All of this points to DXV misnomering DXT5.
diff --git a/libavcodec/dxv.c b/libavcodec/dxv.c index 5923811b29..1e6791e63f 100644 --- a/libavcodec/dxv.c +++ b/libavcodec/dxv.c @@ -1074,7 +1074,8 @@ static int dxv_decode(AVCodecContext *avctx, AVFrame *frame, break; case MKBETAG('D', 'X', 'T', '5'): decompress_tex = dxv_decompress_dxt5; - ctx->tex_funct = ctx->texdsp.dxt5_block; + /* DXV misnomers DXT5, alpha is premultiplied so use DXT4 instead */ + ctx->tex_funct = ctx->texdsp.dxt4_block; ctx->tex_rat = 4; ctx->tex_step = 16; msgcomp = "DXTR5";
DXV files seem to misnomer DXT5 and really encode DXT4 with premultiplied alpha. At least, this is what Resolume alley does. To check, encode some input with alpha as "Normal Quality, With Alpha" in Alley, then decode the output with this change -- results are true to the original input compared to git-master. Signed-off-by: Connor Worley <connorbworley@gmail.com> --- libavcodec/dxv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)