[FFmpeg-cvslog] avcodec/ac3{dec,enc}: Deduplicate gain levels table
Andreas Rheinhardt
git at videolan.org
Mon Jun 2 14:53:38 EEST 2025
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Sat May 24 18:58:24 2025 +0200| [dbd2ca3580fa90ff6d7bf226e9a487f12a2ca3a3] | committer: Andreas Rheinhardt
avcodec/ac3{dec,enc}: Deduplicate gain levels table
(I don't know why the encoder only uses eight of the nine values.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=dbd2ca3580fa90ff6d7bf226e9a487f12a2ca3a3
---
libavcodec/ac3dec.c | 36 ++++++++++++------------------------
libavcodec/ac3enc.c | 5 +----
libavcodec/ac3tab.c | 14 ++++++++++++++
libavcodec/ac3tab.h | 5 +++++
4 files changed, 32 insertions(+), 28 deletions(-)
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index 0e18403793..2b87c7a5f9 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -61,18 +61,6 @@ static float dynamic_range_tab[256];
float ff_ac3_heavy_dynamic_range_tab[256];
#endif
-/** Adjustments in dB gain */
-static const float gain_levels[9] = {
- LEVEL_PLUS_3DB,
- LEVEL_PLUS_1POINT5DB,
- LEVEL_ONE,
- LEVEL_MINUS_1POINT5DB,
- LEVEL_MINUS_3DB,
- LEVEL_MINUS_4POINT5DB,
- LEVEL_MINUS_6DB,
- LEVEL_ZERO,
- LEVEL_MINUS_9DB
-};
/** Adjustments in dB gain (LFE, +10 to -21 dB) */
static const float gain_levels_lfe[32] = {
@@ -346,8 +334,8 @@ static int parse_frame_header(AC3DecodeContext *s)
static int set_downmix_coeffs(AC3DecodeContext *s)
{
int i;
- float cmix = gain_levels[s-> center_mix_level];
- float smix = gain_levels[s->surround_mix_level];
+ float cmix = ff_ac3_gain_levels[s-> center_mix_level];
+ float smix = ff_ac3_gain_levels[s->surround_mix_level];
float norm0, norm1;
float downmix_coeffs[2][AC3_MAX_CHANNELS];
@@ -360,8 +348,8 @@ static int set_downmix_coeffs(AC3DecodeContext *s)
}
for (i = 0; i < s->fbw_channels; i++) {
- downmix_coeffs[0][i] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
- downmix_coeffs[1][i] = gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
+ downmix_coeffs[0][i] = ff_ac3_gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
+ downmix_coeffs[1][i] = ff_ac3_gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
}
if (s->channel_mode > 1 && s->channel_mode & 1) {
downmix_coeffs[0][1] = downmix_coeffs[1][1] = cmix;
@@ -1562,10 +1550,10 @@ dependent_frame:
s->output_mode = AC3_CHMODE_STEREO;
}
- s->loro_center_mix_level = gain_levels[s-> center_mix_level];
- s->loro_surround_mix_level = gain_levels[s->surround_mix_level];
- s->ltrt_center_mix_level = gain_levels[s-> center_mix_level_ltrt];
- s->ltrt_surround_mix_level = gain_levels[s->surround_mix_level_ltrt];
+ s->loro_center_mix_level = ff_ac3_gain_levels[s-> center_mix_level];
+ s->loro_surround_mix_level = ff_ac3_gain_levels[s->surround_mix_level];
+ s->ltrt_center_mix_level = ff_ac3_gain_levels[s-> center_mix_level_ltrt];
+ s->ltrt_surround_mix_level = ff_ac3_gain_levels[s->surround_mix_level_ltrt];
switch (s->preferred_downmix) {
case AC3_DMIXMOD_LTRT:
s->preferred_stereo_downmix = AV_DOWNMIX_TYPE_LTRT;
@@ -1804,10 +1792,10 @@ skip:
downmix_info->preferred_downmix_type = AV_DOWNMIX_TYPE_UNKNOWN;
break;
}
- downmix_info->center_mix_level = gain_levels[s-> center_mix_level];
- downmix_info->center_mix_level_ltrt = gain_levels[s-> center_mix_level_ltrt];
- downmix_info->surround_mix_level = gain_levels[s-> surround_mix_level];
- downmix_info->surround_mix_level_ltrt = gain_levels[s->surround_mix_level_ltrt];
+ downmix_info->center_mix_level = ff_ac3_gain_levels[s-> center_mix_level];
+ downmix_info->center_mix_level_ltrt = ff_ac3_gain_levels[s-> center_mix_level_ltrt];
+ downmix_info->surround_mix_level = ff_ac3_gain_levels[s-> surround_mix_level];
+ downmix_info->surround_mix_level_ltrt = ff_ac3_gain_levels[s->surround_mix_level_ltrt];
if (s->lfe_mix_level_exists)
downmix_info->lfe_mix_level = gain_levels_lfe[s->lfe_mix_level];
else
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index a1783577c5..a316d4e4d7 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -71,10 +71,7 @@ static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
};
#define EXTMIXLEV_NUM_OPTIONS 8
-static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
- LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_1POINT5DB,
- LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
-};
+#define extmixlev_options ff_ac3_gain_levels
/* The first two options apply only to the AC-3 encoders;
* the rest is also valid for EAC-3. When modifying it,
diff --git a/libavcodec/ac3tab.c b/libavcodec/ac3tab.c
index 48c89a8ba0..b38e7237b3 100644
--- a/libavcodec/ac3tab.c
+++ b/libavcodec/ac3tab.c
@@ -25,6 +25,7 @@
*/
#include "libavutil/channel_layout.h"
+#include "libavutil/mathematics.h"
#include "ac3tab.h"
@@ -147,6 +148,19 @@ const uint16_t ff_ac3_fast_gain_tab[8]= {
0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380, 0x400,
};
+/** Adjustments in dB gain */
+const float ff_ac3_gain_levels[9] = {
+ LEVEL_PLUS_3DB,
+ LEVEL_PLUS_1POINT5DB,
+ LEVEL_ONE,
+ LEVEL_MINUS_1POINT5DB,
+ LEVEL_MINUS_3DB,
+ LEVEL_MINUS_4POINT5DB,
+ LEVEL_MINUS_6DB,
+ LEVEL_ZERO,
+ LEVEL_MINUS_9DB
+};
+
const uint64_t ff_eac3_custom_channel_map_locations[16][2] = {
{ 1, AV_CH_FRONT_LEFT },
{ 1, AV_CH_FRONT_CENTER },
diff --git a/libavcodec/ac3tab.h b/libavcodec/ac3tab.h
index dcef643acb..3f83ce7b8c 100644
--- a/libavcodec/ac3tab.h
+++ b/libavcodec/ac3tab.h
@@ -26,6 +26,9 @@
#include "ac3defs.h"
+#include "libavutil/attributes_internal.h"
+
+FF_VISIBILITY_PUSH_HIDDEN
extern const uint16_t ff_ac3_frame_size_tab[38][3];
extern const uint8_t ff_ac3_channels_tab[8];
extern const uint16_t ff_ac3_channel_layout_tab[8];
@@ -43,7 +46,9 @@ extern const int16_t ff_ac3_floor_tab[8];
extern const uint16_t ff_ac3_fast_gain_tab[8];
extern const uint8_t ff_ac3_band_start_tab[AC3_CRITICAL_BANDS+1];
extern const uint8_t ff_ac3_bin_to_band_tab[253];
+extern const float ff_ac3_gain_levels[9];
extern const uint64_t ff_eac3_custom_channel_map_locations[16][2];
+FF_VISIBILITY_POP_HIDDEN
#define COMMON_CHANNEL_MAP \
{ { 0, 1, }, { 0, 1, 2, } },\
More information about the ffmpeg-cvslog
mailing list