Patches attached. None of which are meant to address the fate failure
mentioned by Martin.
- Andreas
From d1a59c3fa3101192256bf67484b0cc9d5f2967b2 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
Date: Wed, 5 Mar 2025 13:57:16 +0100
Subject: [PATCH 1/2] avcodec/exr: Remove write-only gamma_table
Forgotten in 0e917389fe73c932049635d947bba076f1709589.
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
---
libavcodec/exr.c | 31 -------------------------------
1 file changed, 31 deletions(-)
diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 7e8020a0ff..8b673046c1 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -190,7 +190,6 @@ typedef struct EXRContext {
enum AVColorTransferCharacteristic apply_trc_type;
float gamma;
- union av_intfloat32 gamma_table[65536];
uint8_t *offset_table;
@@ -2240,10 +2239,6 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *picture,
static av_cold int decode_init(AVCodecContext *avctx)
{
EXRContext *s = avctx->priv_data;
- uint32_t i;
- union av_intfloat32 t;
- float one_gamma = 1.0f / s->gamma;
- av_csp_trc_function trc_func = NULL;
ff_init_half2float_tables(&s->h2f_tables);
@@ -2255,32 +2250,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
ff_bswapdsp_init(&s->bbdsp);
#endif
- trc_func = av_csp_trc_func_from_id(s->apply_trc_type);
- if (trc_func) {
- for (i = 0; i < 65536; ++i) {
- t.i = half2float(i, &s->h2f_tables);
- t.f = trc_func(t.f);
- s->gamma_table[i] = t;
- }
- } else {
- if (one_gamma > 0.9999f && one_gamma < 1.0001f) {
- for (i = 0; i < 65536; ++i) {
- s->gamma_table[i].i = half2float(i, &s->h2f_tables);
- }
- } else {
- for (i = 0; i < 65536; ++i) {
- t.i = half2float(i, &s->h2f_tables);
- /* If negative value we reuse half value */
- if (t.f <= 0.0f) {
- s->gamma_table[i] = t;
- } else {
- t.f = powf(t.f, one_gamma);
- s->gamma_table[i] = t;
- }
- }
- }
- }
-
// allocate thread data, used for non EXR_RAW compression types
s->thread_data = av_calloc(avctx->thread_count, sizeof(*s->thread_data));
if (!s->thread_data)
--
2.45.2
From a0f2d79445366fda3b485e701c84e69d11148259 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
Date: Wed, 5 Mar 2025 14:19:13 +0100
Subject: [PATCH 2/2] avcodec/exr: Fix potential effective-type violation
Storing the values via a union of an uint32_t and a float makes
said union the effective type of the destination. This means that
it may only be read via such a union which is of course not what
our users do/expect. So store the values via AV_WN32A instead
which disables effective type analysis (for compilers that perform it).
This also fixes a -Wdeclaration-after-statement warning
introduced in 0e917389fe73c932049635d947bba076f1709589.
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
---
libavcodec/exr.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)
diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 8b673046c1..1c753edb9f 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1383,34 +1383,29 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
s->compression == EXR_DWAA ||
s->compression == EXR_DWAB) {
// 32-bit
- union av_intfloat32 *ptr_x;
+ uint8_t *ptr_x = ptr;
src = channel_buffer[c];
- ptr_x = (union av_intfloat32 *)ptr;
// Zero out the start if xmin is not 0
memset(ptr_x, 0, bxmin);
- ptr_x += window_xoffset;
+ ptr_x += 4 * window_xoffset;
- union av_intfloat32 t;
if (trc_func && c < 3) {
- for (x = 0; x < xsize; x++) {
- t.i = bytestream_get_le32(&src);
- t.f = trc_func(t.f);
- *ptr_x++ = t;
+ for (int x = 0; x < xsize; x++, ptr_x += 4) {
+ float f = av_int2float(bytestream_get_le32(&src));
+ AV_WN32A(ptr_x, av_float2int(trc_func(f)));
}
} else if (one_gamma != 1.f) {
- for (x = 0; x < xsize; x++) {
- t.i = bytestream_get_le32(&src);
- if (t.f > 0.0f && c < 3) /* avoid negative values */
- t.f = powf(t.f, one_gamma);
- *ptr_x++ = t;
+ for (int x = 0; x < xsize; x++, ptr_x += 4) {
+ float f = av_int2float(bytestream_get_le32(&src));
+ if (f > 0.0f && c < 3) /* avoid negative values */
+ f = powf(f, one_gamma);
+ AV_WN32A(ptr_x, av_float2int(f));
}
} else {
- for (x = 0; x < xsize; x++) {
- t.i = bytestream_get_le32(&src);
- *ptr_x++ = t;
- }
+ for (int x = 0; x < xsize; x++, ptr_x += 4)
+ AV_WN32A(ptr_x, bytestream_get_le32(&src));
}
memset(ptr_x, 0, axmax);
} else if (s->pixel_type == EXR_HALF) {
--
2.45.2
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