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Linshizhi
ffmpeg.wasm-core
Commits
68233767
Commit
68233767
authored
Jun 28, 2009
by
Vladimir Voroshilov
Committed by
Michael Niedermayer
Sep 24, 2011
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Adaptive gain control
parent
aca516cd
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3 changed files
with
89 additions
and
0 deletions
+89
-0
g729dec.c
libavcodec/g729dec.c
+21
-0
g729postfilter.c
libavcodec/g729postfilter.c
+48
-0
g729postfilter.h
libavcodec/g729postfilter.h
+20
-0
No files found.
libavcodec/g729dec.c
View file @
68233767
...
@@ -145,6 +145,7 @@ typedef struct {
...
@@ -145,6 +145,7 @@ typedef struct {
int16_t
onset
;
///< detected onset level (0-2)
int16_t
onset
;
///< detected onset level (0-2)
int16_t
was_periodic
;
///< whether previous frame was declared as periodic or not (4.4)
int16_t
was_periodic
;
///< whether previous frame was declared as periodic or not (4.4)
int16_t
ht_prev_data
;
///< previous data for 4.2.3, equation 86
int16_t
ht_prev_data
;
///< previous data for 4.2.3, equation 86
int
gain_coeff
;
///< (1.14) gain coefficient (4.2.4)
uint16_t
rand_value
;
///< random number generator value (4.4.4)
uint16_t
rand_value
;
///< random number generator value (4.4.4)
int
ma_predictor_prev
;
///< switched MA predictor of LSP quantizer from last good frame
int
ma_predictor_prev
;
///< switched MA predictor of LSP quantizer from last good frame
...
@@ -348,6 +349,8 @@ static av_cold int decoder_init(AVCodecContext * avctx)
...
@@ -348,6 +349,8 @@ static av_cold int decoder_init(AVCodecContext * avctx)
/* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
/* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
avctx
->
frame_size
=
SUBFRAME_SIZE
<<
1
;
avctx
->
frame_size
=
SUBFRAME_SIZE
<<
1
;
ctx
->
gain_coeff
=
16384
;
// 1.0 in (1.14)
for
(
k
=
0
;
k
<
MA_NP
+
1
;
k
++
)
{
for
(
k
=
0
;
k
<
MA_NP
+
1
;
k
++
)
{
ctx
->
past_quantizer_outputs
[
k
]
=
ctx
->
past_quantizer_output_buf
[
k
];
ctx
->
past_quantizer_outputs
[
k
]
=
ctx
->
past_quantizer_output_buf
[
k
];
for
(
i
=
1
;
i
<
11
;
i
++
)
for
(
i
=
1
;
i
<
11
;
i
++
)
...
@@ -397,6 +400,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
...
@@ -397,6 +400,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
int16_t
fc
[
SUBFRAME_SIZE
];
// fixed-codebook vector
int16_t
fc
[
SUBFRAME_SIZE
];
// fixed-codebook vector
int16_t
synth
[
SUBFRAME_SIZE
+
10
];
// fixed-codebook vector
int16_t
synth
[
SUBFRAME_SIZE
+
10
];
// fixed-codebook vector
int
j
;
int
j
;
int
gain_before
,
gain_after
;
int
is_periodic
=
0
;
// whether one of the subframes is declared as periodic or not
int
is_periodic
=
0
;
// whether one of the subframes is declared as periodic or not
if
(
*
data_size
<
SUBFRAME_SIZE
<<
2
)
{
if
(
*
data_size
<
SUBFRAME_SIZE
<<
2
)
{
...
@@ -637,6 +641,11 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
...
@@ -637,6 +641,11 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
/* Save data (without postfilter) for use in next subframe. */
/* Save data (without postfilter) for use in next subframe. */
memcpy
(
ctx
->
syn_filter_data
,
synth
+
SUBFRAME_SIZE
,
10
*
sizeof
(
int16_t
));
memcpy
(
ctx
->
syn_filter_data
,
synth
+
SUBFRAME_SIZE
,
10
*
sizeof
(
int16_t
));
/* Calculate gain of unfiltered signal for use in AGC. */
gain_before
=
0
;
for
(
j
=
0
;
j
<
SUBFRAME_SIZE
;
j
++
)
gain_before
+=
FFABS
(
synth
[
j
+
10
]);
/* Call postfilter and also update voicing decision for use in next frame. */
/* Call postfilter and also update voicing decision for use in next frame. */
g729_postfilter
(
g729_postfilter
(
&
ctx
->
dsp
,
&
ctx
->
dsp
,
...
@@ -650,6 +659,18 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
...
@@ -650,6 +659,18 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
synth
+
10
,
synth
+
10
,
SUBFRAME_SIZE
);
SUBFRAME_SIZE
);
/* Calculate gain of filtered signal for use in AGC. */
gain_after
=
0
;
for
(
j
=
0
;
j
<
SUBFRAME_SIZE
;
j
++
)
gain_after
+=
FFABS
(
synth
[
j
+
10
]);
ctx
->
gain_coeff
=
g729_adaptive_gain_control
(
gain_before
,
gain_after
,
synth
+
10
,
SUBFRAME_SIZE
,
ctx
->
gain_coeff
);
if
(
frame_erasure
)
if
(
frame_erasure
)
ctx
->
pitch_delay_int_prev
=
FFMIN
(
ctx
->
pitch_delay_int_prev
+
1
,
PITCH_DELAY_MAX
);
ctx
->
pitch_delay_int_prev
=
FFMIN
(
ctx
->
pitch_delay_int_prev
+
1
,
PITCH_DELAY_MAX
);
else
else
...
...
libavcodec/g729postfilter.c
View file @
68233767
...
@@ -560,3 +560,51 @@ void g729_postfilter(DSPContext *dsp, int16_t* ht_prev_data, int16_t* voicing,
...
@@ -560,3 +560,51 @@ void g729_postfilter(DSPContext *dsp, int16_t* ht_prev_data, int16_t* voicing,
*
ht_prev_data
=
apply_tilt_comp
(
speech
,
pos_filter_data
+
10
,
tilt_comp_coeff
,
*
ht_prev_data
=
apply_tilt_comp
(
speech
,
pos_filter_data
+
10
,
tilt_comp_coeff
,
subframe_size
,
*
ht_prev_data
);
subframe_size
,
*
ht_prev_data
);
}
}
/**
* \brief Adaptive gain control (4.2.4)
* \param gain_before gain of speech before applying postfilters
* \param gain_after gain of speech after applying postfilters
* \param speech [in/out] signal buffer
* \param subframe_size length of subframe
* \param gain_prev (3.12) previous value of gain coefficient
*
* \return (3.12) last value of gain coefficient
*/
int16_t
g729_adaptive_gain_control
(
int
gain_before
,
int
gain_after
,
int16_t
*
speech
,
int
subframe_size
,
int16_t
gain_prev
)
{
int
gain
;
// (3.12)
int
n
;
int
exp_before
,
exp_after
;
if
(
!
gain_after
&&
gain_before
)
return
0
;
if
(
gain_before
)
{
exp_before
=
14
-
av_log2
(
gain_before
);
gain_before
=
bidir_sal
(
gain_before
,
exp_before
);
exp_after
=
14
-
av_log2
(
gain_after
);
gain_after
=
bidir_sal
(
gain_after
,
exp_after
);
if
(
gain_before
<
gain_after
)
{
gain
=
(
gain_before
<<
15
)
/
gain_after
;
gain
=
bidir_sal
(
gain
,
exp_after
-
exp_before
-
1
);
}
else
{
gain
=
((
gain_before
-
gain_after
)
<<
14
)
/
gain_after
+
0x4000
;
gain
=
bidir_sal
(
gain
,
exp_after
-
exp_before
);
}
gain
=
(
gain
*
G729_AGC_FAC1
+
0x4000
)
>>
15
;
// gain * (1-0.9875)
}
else
gain
=
0
;
for
(
n
=
0
;
n
<
subframe_size
;
n
++
)
{
// gain_prev = gain + 0.9875 * gain_prev
gain_prev
=
(
G729_AGC_FACTOR
*
gain_prev
+
0x4000
)
>>
15
;
gain_prev
=
av_clip_int16
(
gain
+
gain_prev
);
speech
[
n
]
=
av_clip_int16
((
speech
[
n
]
*
gain_prev
+
0x2000
)
>>
14
);
}
return
gain_prev
;
}
libavcodec/g729postfilter.h
View file @
68233767
...
@@ -39,6 +39,13 @@
...
@@ -39,6 +39,13 @@
#define FORMANT_PP_FACTOR_NUM 18022 //0.55 in Q15
#define FORMANT_PP_FACTOR_NUM 18022 //0.55 in Q15
#define FORMANT_PP_FACTOR_DEN 22938 //0.70 in Q15
#define FORMANT_PP_FACTOR_DEN 22938 //0.70 in Q15
/**
* gain adjustment factor (G.729, 4.2.4)
* 0.9875 in Q15
*/
#define G729_AGC_FACTOR 32358
#define G729_AGC_FAC1 (32768-G729_AGC_FACTOR)
/**
/**
* 1.0 / (1.0 + 0.5) in Q15
* 1.0 / (1.0 + 0.5) in Q15
* where 0.5 is the minimum value of
* where 0.5 is the minimum value of
...
@@ -92,4 +99,17 @@ void g729_postfilter(DSPContext *dsp, int16_t* ht_prev_data, int16_t* voicing,
...
@@ -92,4 +99,17 @@ void g729_postfilter(DSPContext *dsp, int16_t* ht_prev_data, int16_t* voicing,
int16_t
*
pos_filter_data
,
int16_t
*
speech
,
int16_t
*
pos_filter_data
,
int16_t
*
speech
,
int
subframe_size
);
int
subframe_size
);
/**
* \brief Adaptive gain control (4.2.4)
* \param gain_before (Q0) gain of speech before applying postfilters
* \param gain_after (Q0) gain of speech after applying postfilters
* \param speech [in/out] (Q0) signal buffer
* \param subframe_size length of subframe
* \param gain_prev (Q12) previous value of gain coefficient
*
* \return (Q12) last value of gain coefficient
*/
int16_t
g729_adaptive_gain_control
(
int
gain_before
,
int
gain_after
,
int16_t
*
speech
,
int
subframe_size
,
int16_t
gain_prev
);
#endif // FFMPEG_G729POSTFILTER_H
#endif // FFMPEG_G729POSTFILTER_H
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