summaryrefslogtreecommitdiff
path: root/libavcodec/golomb.h
diff options
context:
space:
mode:
Diffstat (limited to 'libavcodec/golomb.h')
-rw-r--r--libavcodec/golomb.h110
1 files changed, 50 insertions, 60 deletions
diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index 398fe3b30a..0d2af4b6aa 100644
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@@ -3,20 +3,20 @@
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
* Copyright (c) 2004 Alex Beregszaszi
*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
@@ -48,7 +48,7 @@ extern const int8_t ff_interleaved_se_golomb_vlc_code[256];
extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
/**
- * read unsigned exp golomb code.
+ * Read an unsigned Exp-Golomb code in the range 0 to 8190.
*/
static inline int get_ue_golomb(GetBitContext *gb)
{
@@ -66,10 +66,14 @@ static inline int get_ue_golomb(GetBitContext *gb)
return ff_ue_golomb_vlc_code[buf];
} else {
int log = 2 * av_log2(buf) - 31;
- buf >>= log;
- buf--;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
+ if (log < 7) {
+ av_log(NULL, AV_LOG_ERROR, "Invalid UE golomb code\n");
+ return AVERROR_INVALIDDATA;
+ }
+ buf >>= log;
+ buf--;
return buf;
}
@@ -138,7 +142,7 @@ static inline unsigned svq3_get_ue_golomb(GetBitContext *gb)
ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
UPDATE_CACHE(re, gb);
buf = GET_CACHE(re, gb);
- } while (BITS_AVAILABLE(re, gb));
+ } while (ret<0x8000000U && BITS_AVAILABLE(re, gb));
CLOSE_READER(re, gb);
return ret - 1;
@@ -150,7 +154,7 @@ static inline unsigned svq3_get_ue_golomb(GetBitContext *gb)
*/
static inline int get_te0_golomb(GetBitContext *gb, int range)
{
- assert(range >= 1);
+ av_assert2(range >= 1);
if (range == 1)
return 0;
@@ -165,7 +169,7 @@ static inline int get_te0_golomb(GetBitContext *gb, int range)
*/
static inline int get_te_golomb(GetBitContext *gb, int range)
{
- assert(range >= 1);
+ av_assert2(range >= 1);
if (range == 2)
return get_bits1(gb) ^ 1;
@@ -191,16 +195,18 @@ static inline int get_se_golomb(GetBitContext *gb)
return ff_se_golomb_vlc_code[buf];
} else {
- int log = 2 * av_log2(buf) - 31;
+ int log = av_log2(buf), sign;
+ LAST_SKIP_BITS(re, gb, 31 - log);
+ UPDATE_CACHE(re, gb);
+ buf = GET_CACHE(re, gb);
+
buf >>= log;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
- if (buf & 1)
- buf = -(buf >> 1);
- else
- buf = (buf >> 1);
+ sign = -(buf & 1);
+ buf = ((buf >> 1) ^ sign) - sign;
return buf;
}
@@ -209,13 +215,8 @@ static inline int get_se_golomb(GetBitContext *gb)
static inline int get_se_golomb_long(GetBitContext *gb)
{
unsigned int buf = get_ue_golomb_long(gb);
-
- if (buf & 1)
- buf = (buf + 1) >> 1;
- else
- buf = -(buf >> 1);
-
- return buf;
+ int sign = (buf & 1) - 1;
+ return ((buf >> 1) ^ sign) + 1;
}
static inline int svq3_get_se_golomb(GetBitContext *gb)
@@ -256,13 +257,8 @@ static inline int dirac_get_se_golomb(GetBitContext *gb)
uint32_t ret = svq3_get_ue_golomb(gb);
if (ret) {
- uint32_t buf;
- OPEN_READER(re, gb);
- UPDATE_CACHE(re, gb);
- buf = SHOW_SBITS(re, gb, 1);
- LAST_SKIP_BITS(re, gb, 1);
- ret = (ret ^ buf) - buf;
- CLOSE_READER(re, gb);
+ int sign = -get_bits1(gb);
+ ret = (ret ^ sign) - sign;
}
return ret;
@@ -285,7 +281,7 @@ static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
if (log > 31 - limit) {
buf >>= log - k;
- buf += (30 - log) << k;
+ buf += (30U - log) << k;
LAST_SKIP_BITS(re, gb, 32 + k - log);
CLOSE_READER(re, gb);
@@ -321,14 +317,16 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
32 - log < limit) {
buf >>= log - k;
- buf += (30 - log) << k;
+ buf += (30U - log) << k;
LAST_SKIP_BITS(re, gb, 32 + k - log);
CLOSE_READER(re, gb);
return buf;
} else {
int i;
- for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0 && BITS_AVAILABLE(re, gb); i++) {
+ for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
+ if (gb->size_in_bits <= re_index)
+ return -1;
LAST_SKIP_BITS(re, gb, 1);
UPDATE_CACHE(re, gb);
}
@@ -336,8 +334,16 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
if (i < limit - 1) {
if (k) {
- buf = SHOW_UBITS(re, gb, k);
- LAST_SKIP_BITS(re, gb, k);
+ if (k > MIN_CACHE_BITS - 1) {
+ buf = SHOW_UBITS(re, gb, 16) << (k-16);
+ LAST_SKIP_BITS(re, gb, 16);
+ UPDATE_CACHE(re, gb);
+ buf |= SHOW_UBITS(re, gb, k-16);
+ LAST_SKIP_BITS(re, gb, k-16);
+ } else {
+ buf = SHOW_UBITS(re, gb, k);
+ LAST_SKIP_BITS(re, gb, k);
+ }
} else {
buf = 0;
}
@@ -361,15 +367,8 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
int esc_len)
{
- int v = get_ur_golomb(gb, k, limit, esc_len);
-
- v++;
- if (v & 1)
- return v >> 1;
- else
- return -(v >> 1);
-
-// return (v>>1) ^ -(v&1);
+ unsigned v = get_ur_golomb(gb, k, limit, esc_len);
+ return (v >> 1) ^ -(v & 1);
}
/**
@@ -378,7 +377,7 @@ static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
int esc_len)
{
- int v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
+ unsigned v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
return (v >> 1) ^ -(v & 1);
}
@@ -396,10 +395,7 @@ static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k)
static inline int get_sr_golomb_shorten(GetBitContext *gb, int k)
{
int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
- if (uvar & 1)
- return ~(uvar >> 1);
- else
- return uvar >> 1;
+ return (uvar >> 1) ^ -(uvar & 1);
}
#ifdef TRACE
@@ -461,14 +457,8 @@ static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
*/
static inline void set_ue_golomb(PutBitContext *pb, int i)
{
- assert(i >= 0);
+ av_assert2(i >= 0);
-#if 0
- if (i = 0) {
- put_bits(pb, 1, 1);
- return;
- }
-#endif
if (i < 256)
put_bits(pb, ff_ue_golomb_len[i], i + 1);
else {
@@ -482,8 +472,8 @@ static inline void set_ue_golomb(PutBitContext *pb, int i)
*/
static inline void set_te_golomb(PutBitContext *pb, int i, int range)
{
- assert(range >= 1);
- assert(i <= range);
+ av_assert2(range >= 1);
+ av_assert2(i <= range);
if (range == 2)
put_bits(pb, 1, i ^ 1);
@@ -520,11 +510,11 @@ static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
{
int e;
- assert(i >= 0);
+ av_assert2(i >= 0);
e = i >> k;
if (e < limit)
- put_bits(pb, e + k + 1, (1 << k) + (i & ((1 << k) - 1)));
+ put_bits(pb, e + k + 1, (1 << k) + av_mod_uintp2(i, k));
else
put_bits(pb, limit + esc_len, i - limit + 1);
}
@@ -537,7 +527,7 @@ static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
{
int e;
- assert(i >= 0);
+ av_assert2(i >= 0);
e = (i >> k) + 1;
if (e < limit) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 14:35:07 +0000