mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2025-01-20 06:11:04 +00:00
atrac3: Generalize gain compensation code
Move it to the ATRAC common code, so it can be reused in the umpcoming ATRAC3+ decoder. Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Maxim Poliakovski
Michael Niedermayer
parent
4fa2484067
commit
d49f3fa579
@ -63,6 +63,67 @@ av_cold void ff_atrac_generate_tables(void)
|
||||
}
|
||||
}
|
||||
|
||||
av_cold void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
|
||||
int loc_scale)
|
||||
{
|
||||
int i;
|
||||
|
||||
gctx->loc_scale = loc_scale;
|
||||
gctx->loc_size = 1 << loc_scale;
|
||||
gctx->id2exp_offset = id2exp_offset;
|
||||
|
||||
/* Generate gain level table. */
|
||||
for (i = 0; i < 16; i++)
|
||||
gctx->gain_tab1[i] = powf(2.0, id2exp_offset - i);
|
||||
|
||||
/* Generate gain interpolation table. */
|
||||
for (i = -15; i < 16; i++)
|
||||
gctx->gain_tab2[i + 15] = powf(2.0, -1.0f / gctx->loc_size * i);
|
||||
}
|
||||
|
||||
void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
|
||||
AtracGainInfo *gc_now, AtracGainInfo *gc_next,
|
||||
int num_samples, float *out)
|
||||
{
|
||||
float lev, gc_scale, gain_inc;
|
||||
int i, pos, lastpos;
|
||||
|
||||
gc_scale = gc_next->num_points ? gctx->gain_tab1[gc_next->levcode[0]] : 1.0f;
|
||||
|
||||
if (!gc_now->num_points) {
|
||||
for (pos = 0; pos < num_samples; pos++)
|
||||
out[pos] = in[pos] * gc_scale + prev[pos];
|
||||
} else {
|
||||
pos = 0;
|
||||
|
||||
for (i = 0; i < gc_now->num_points; i++) {
|
||||
lastpos = gc_now->loccode[i] << gctx->loc_scale;
|
||||
|
||||
lev = gctx->gain_tab1[gc_now->levcode[i]];
|
||||
gain_inc = gctx->gain_tab2[(i + 1 < gc_now->num_points
|
||||
? gc_now->levcode[i + 1]
|
||||
: gctx->id2exp_offset)
|
||||
- gc_now->levcode[i] + 15];
|
||||
|
||||
/* apply constant gain level and overlap */
|
||||
for (; pos < lastpos; pos++)
|
||||
out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;
|
||||
|
||||
/* interpolate between two different gain levels */
|
||||
for (; pos < lastpos + gctx->loc_size; pos++) {
|
||||
out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;
|
||||
lev *= gain_inc;
|
||||
}
|
||||
}
|
||||
|
||||
for (; pos < num_samples; pos++)
|
||||
out[pos] = in[pos] * gc_scale + prev[pos];
|
||||
}
|
||||
|
||||
/* copy the overlapping part into the delay buffer */
|
||||
memcpy(prev, &in[num_samples], num_samples * sizeof(float));
|
||||
}
|
||||
|
||||
void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut,
|
||||
float *delayBuf, float *temp)
|
||||
{
|
||||
|
||||
@ -29,6 +29,26 @@
|
||||
#ifndef AVCODEC_ATRAC_H
|
||||
#define AVCODEC_ATRAC_H
|
||||
|
||||
/**
|
||||
* Gain control parameters for one subband.
|
||||
*/
|
||||
typedef struct AtracGainInfo {
|
||||
int num_points; ///< number of gain control points
|
||||
int levcode[7]; ///< level at corresponding control point
|
||||
int loccode[7]; ///< location of gain control points
|
||||
} AtracGainInfo;
|
||||
|
||||
/**
|
||||
* Gain compensation context structure.
|
||||
*/
|
||||
typedef struct AtracGCContext {
|
||||
float gain_tab1[16]; ///< gain compensation level table
|
||||
float gain_tab2[31]; ///< gain compensation interpolation table
|
||||
int id2exp_offset; ///< offset for converting level index into level exponent
|
||||
int loc_scale; ///< scale of location code = 2^loc_scale samples
|
||||
int loc_size; ///< size of location code in samples
|
||||
} AtracGCContext;
|
||||
|
||||
extern float ff_atrac_sf_table[64];
|
||||
|
||||
/**
|
||||
@ -36,6 +56,31 @@ extern float ff_atrac_sf_table[64];
|
||||
*/
|
||||
void ff_atrac_generate_tables(void);
|
||||
|
||||
/**
|
||||
* Initialize gain compensation context.
|
||||
*
|
||||
* @param gctx pointer to gain compensation context to initialize
|
||||
* @param id2exp_offset offset for converting level index into level exponent
|
||||
* @param loc_scale location size factor
|
||||
*/
|
||||
void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
|
||||
int loc_scale);
|
||||
|
||||
/**
|
||||
* Apply gain compensation and perform the MDCT overlapping part.
|
||||
*
|
||||
* @param gctx pointer to gain compensation context
|
||||
* @param in input buffer
|
||||
* @param prev previous buffer to perform overlap against
|
||||
* @param gc_now gain control information for current frame
|
||||
* @param gc_next gain control information for next frame
|
||||
* @param num_samples number of samples to process
|
||||
* @param out output data goes here
|
||||
*/
|
||||
void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
|
||||
AtracGainInfo *gc_now, AtracGainInfo *gc_next,
|
||||
int num_samples, float *out);
|
||||
|
||||
/**
|
||||
* Quadrature mirror synthesis filter.
|
||||
*
|
||||
|
||||
@ -55,12 +55,6 @@
|
||||
#define SAMPLES_PER_FRAME 1024
|
||||
#define MDCT_SIZE 512
|
||||
|
||||
typedef struct AtracGainInfo {
|
||||
int num_points;
|
||||
int lev_code[8];
|
||||
int loc_code[8];
|
||||
} AtracGainInfo;
|
||||
|
||||
typedef struct GainBlock {
|
||||
AtracGainInfo g_block[4];
|
||||
} GainBlock;
|
||||
@ -112,7 +106,8 @@ typedef struct ATRAC3Context {
|
||||
int scrambled_stream;
|
||||
//@}
|
||||
|
||||
FFTContext mdct_ctx;
|
||||
AtracGCContext gainc_ctx;
|
||||
FFTContext mdct_ctx;
|
||||
FmtConvertContext fmt_conv;
|
||||
AVFloatDSPContext fdsp;
|
||||
} ATRAC3Context;
|
||||
@ -443,63 +438,6 @@ static int decode_gain_control(GetBitContext *gb, GainBlock *block,
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Apply gain parameters and perform the MDCT overlapping part
|
||||
*
|
||||
* @param input input buffer
|
||||
* @param prev previous buffer to perform overlap against
|
||||
* @param output output buffer
|
||||
* @param gain1 current band gain info
|
||||
* @param gain2 next band gain info
|
||||
*/
|
||||
static void gain_compensate_and_overlap(float *input, float *prev,
|
||||
float *output, AtracGainInfo *gain1,
|
||||
AtracGainInfo *gain2)
|
||||
{
|
||||
float g1, g2, gain_inc;
|
||||
int i, j, num_data, start_loc, end_loc;
|
||||
|
||||
|
||||
if (gain2->num_points == 0)
|
||||
g1 = 1.0;
|
||||
else
|
||||
g1 = gain_tab1[gain2->lev_code[0]];
|
||||
|
||||
if (gain1->num_points == 0) {
|
||||
for (i = 0; i < 256; i++)
|
||||
output[i] = input[i] * g1 + prev[i];
|
||||
} else {
|
||||
num_data = gain1->num_points;
|
||||
gain1->loc_code[num_data] = 32;
|
||||
gain1->lev_code[num_data] = 4;
|
||||
|
||||
for (i = 0, j = 0; i < num_data; i++) {
|
||||
start_loc = gain1->loc_code[i] * 8;
|
||||
end_loc = start_loc + 8;
|
||||
|
||||
g2 = gain_tab1[gain1->lev_code[i]];
|
||||
gain_inc = gain_tab2[gain1->lev_code[i + 1] -
|
||||
gain1->lev_code[i ] + 15];
|
||||
|
||||
/* interpolate */
|
||||
for (; j < start_loc; j++)
|
||||
output[j] = (input[j] * g1 + prev[j]) * g2;
|
||||
|
||||
/* interpolation is done over eight samples */
|
||||
for (; j < end_loc; j++) {
|
||||
output[j] = (input[j] * g1 + prev[j]) * g2;
|
||||
g2 *= gain_inc;
|
||||
}
|
||||
}
|
||||
|
||||
for (; j < 256; j++)
|
||||
output[j] = input[j] * g1 + prev[j];
|
||||
}
|
||||
|
||||
/* Delay for the overlapping part. */
|
||||
memcpy(prev, &input[256], 256 * sizeof(*prev));
|
||||
}
|
||||
|
||||
/**
|
||||
* Combine the tonal band spectrum and regular band spectrum
|
||||
*
|
||||
@ -690,11 +628,10 @@ static int decode_channel_sound_unit(ATRAC3Context *q, GetBitContext *gb,
|
||||
memset(snd->imdct_buf, 0, 512 * sizeof(*snd->imdct_buf));
|
||||
|
||||
/* gain compensation and overlapping */
|
||||
gain_compensate_and_overlap(snd->imdct_buf,
|
||||
&snd->prev_frame[band * 256],
|
||||
&output[band * 256],
|
||||
&gain1->g_block[band],
|
||||
&gain2->g_block[band]);
|
||||
ff_atrac_gain_compensation(&q->gainc_ctx, snd->imdct_buf,
|
||||
&snd->prev_frame[band * 256],
|
||||
&gain1->g_block[band], &gain2->g_block[band],
|
||||
256, &output[band * 256]);
|
||||
}
|
||||
|
||||
/* Swap the gain control buffers for the next frame. */
|
||||
@ -987,6 +924,7 @@ static av_cold int atrac3_decode_init(AVCodecContext *avctx)
|
||||
q->matrix_coeff_index_next[i] = 3;
|
||||
}
|
||||
|
||||
ff_atrac_init_gain_compensation(&q->gainc_ctx, 4, 3);
|
||||
avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
|
||||
ff_fmt_convert_init(&q->fmt_conv, avctx);
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user