From 5956d3424e2eb7c2419dcbf026cb28eee0d880fd Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Fri, 7 Mar 2025 02:06:40 +0100
Subject: [PATCH 3/9] avcodec/vc1_block: Stop setting write-only
block_last_index
It is only used by the mpegvideo unquantize functions which
this decoder does not use at all.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
libavcodec/vc1_block.c | 32 +++++++++-----------------------
1 file changed, 9 insertions(+), 23 deletions(-)
diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c
index 8babbde38c..26adfbca1d 100644
--- a/libavcodec/vc1_block.c
+++ b/libavcodec/vc1_block.c
@@ -585,7 +585,6 @@ static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
GetBitContext *gb = &v->s.gb;
MpegEncContext *s = &v->s;
int dc_pred_dir = 0; /* Direction of the DC prediction used */
- int i;
int16_t *dc_val;
int16_t *ac_val, *ac_val2;
int dcdiff, scale;
@@ -622,7 +621,6 @@ static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
scale = v->pq * 2 + v->halfpq;
//AC Decoding
- i = !!coded;
if (coded) {
int last = 0, skip, value;
@@ -637,14 +635,14 @@ static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
} else
zz_table = v->zz_8x8[1];
- while (!last) {
+ for (int i = 1; !last; ++i) {
int ret = vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
if (ret < 0)
return ret;
i += skip;
if (i > 63)
break;
- block[zz_table[i++]] = value;
+ block[zz_table[i]] = value;
}
/* apply AC prediction if needed */
@@ -696,8 +694,6 @@ static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
}
}
}
- if (s->ac_pred) i = 63;
- s->block_last_index[n] = i;
return 0;
}
@@ -716,7 +712,6 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
GetBitContext *gb = &v->s.gb;
MpegEncContext *s = &v->s;
int dc_pred_dir = 0; /* Direction of the DC prediction used */
- int i;
int16_t *dc_val = NULL;
int16_t *ac_val, *ac_val2;
int dcdiff;
@@ -778,7 +773,6 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
}
//AC Decoding
- i = 1;
if (coded) {
int last = 0, skip, value;
@@ -801,14 +795,14 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
zz_table = v->zzi_8x8;
}
- while (!last) {
+ for (int i = 1; !last; ++i) {
int ret = vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
if (ret < 0)
return ret;
i += skip;
if (i > 63)
break;
- block[zz_table[i++]] = value;
+ block[zz_table[i]] = value;
}
/* apply AC prediction if needed */
@@ -880,8 +874,6 @@ static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
}
}
}
- if (use_pred) i = 63;
- s->block_last_index[n] = i;
return 0;
}
@@ -900,7 +892,6 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
GetBitContext *gb = &v->s.gb;
MpegEncContext *s = &v->s;
int dc_pred_dir = 0; /* Direction of the DC prediction used */
- int i;
int16_t *dc_val = NULL;
int16_t *ac_val, *ac_val2;
int dcdiff;
@@ -942,7 +933,6 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
block[0] = dcdiff * s->y_dc_scale;
//AC Decoding
- i = 1;
/* check if AC is needed at all and adjust direction if needed */
if (!a_avail) dc_pred_dir = 1;
@@ -973,7 +963,7 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
int last = 0, skip, value;
int k;
- while (!last) {
+ for (int i = 1; !last; ++i) {
int ret = vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
if (ret < 0)
return ret;
@@ -981,15 +971,15 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
if (i > 63)
break;
if (v->fcm == PROGRESSIVE)
- block[v->zz_8x8[0][i++]] = value;
+ block[v->zz_8x8[0][i]] = value;
else {
if (use_pred && (v->fcm == ILACE_FRAME)) {
if (!dc_pred_dir) // top
- block[v->zz_8x8[2][i++]] = value;
+ block[v->zz_8x8[2][i]] = value;
else // left
- block[v->zz_8x8[3][i++]] = value;
+ block[v->zz_8x8[3][i]] = value;
} else {
- block[v->zzi_8x8[i++]] = value;
+ block[v->zzi_8x8[i]] = value;
}
}
}
@@ -1033,8 +1023,6 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
if (!v->pquantizer)
block[k] += (block[k] < 0) ? -quant : quant;
}
-
- if (use_pred) i = 63;
} else { // no AC coeffs
int k;
@@ -1082,10 +1070,8 @@ static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -quant : quant;
}
}
- i = 63;
}
}
- s->block_last_index[n] = i;
return 0;
}
--
2.45.2