From 8842a69091b5eb5cf9b704b3ff504d21db4aad9b Mon Sep 17 00:00:00 2001
From: Ivan Kalvachev <ikalvachev@gmail.com>
Date: Mon, 9 Oct 2017 01:25:00 +0300
Subject: [PATCH] Fix visual glitch with XvMC, caused by wrong idct
permutation.
In the past XvMC forced simple_idct since
it was using FF_IDCT_PERM_NONE.
However now we have SIMD variants of simple_idct that
are using FF_IDCT_PERM_TRANSPOSE and if they are selected
XvMC would get coefficients in the wrong order.
The patch creates new FF_IDCT_NONE that
is used only for this kind of hardware decoding
and that fallbacks to the old C only simple idct.
Signed-off-by: Ivan Kalvachev <ikalvachev@gmail.com>
---
libavcodec/avcodec.h | 1 +
libavcodec/idctdsp.c | 1 +
libavcodec/mpeg12dec.c | 2 +-
3 files changed, 3 insertions(+), 1 deletion(-)
@@ -3146,6 +3146,7 @@ typedef struct AVCodecContext {
#if FF_API_ARCH_ALPHA
#define FF_IDCT_SIMPLEALPHA 23
#endif
+#define FF_IDCT_NONE 24 /* Used by XvMC to extract IDCT coefficients with FF_IDCT_PERM_NONE */
#define FF_IDCT_SIMPLEAUTO 128
/**
@@ -279,6 +279,7 @@ av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
c->perm_type = FF_IDCT_PERM_NONE;
#endif /* CONFIG_FAANIDCT */
} else { // accurate/default
+ /* Be sure FF_IDCT_NONE will select this one, since it uses FF_IDCT_PERM_NONE */
c->idct_put = ff_simple_idct_put_8;
c->idct_add = ff_simple_idct_add_8;
c->idct = ff_simple_idct_8;
@@ -1217,7 +1217,7 @@ static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
#endif
)
if (avctx->idct_algo == FF_IDCT_AUTO)
- avctx->idct_algo = FF_IDCT_SIMPLE;
+ avctx->idct_algo = FF_IDCT_NONE;
if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
Mpeg1Context *s1 = avctx->priv_data;
--
2.14.1