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Implement QCELP postfilter.

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Originally committed as revision 22935 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Ronald S. Bultje 2010-04-21 17:50:08 +00:00
parent 5180a0b197
commit 805a83d506
1 changed files with 41 additions and 5 deletions
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46
libavcodec/qcelpdec.c
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@ -37,6 +37,7 @@
#include "celp_math.h"
#include "celp_filters.h"
#include "acelp_filters.h"
#include "acelp_vectors.h"
#include "lsp.h"
@ -74,6 +75,11 @@ typedef struct
uint8_t pitch_lag[4];
uint16_t first16bits;
uint8_t warned_buf_mismatch_bitrate;
/* postfilter */
float postfilter_synth_mem[10];
float postfilter_agc_mem;
float postfilter_tilt_mem;
} QCELPContext;
/**
@ -695,6 +701,36 @@ static void warn_insufficient_frame_quality(AVCodecContext *avctx,
message);
}
static void postfilter(QCELPContext *q, float *samples, float *lpc)
{
static const float pow_0_775[10] = {
0.775000, 0.600625, 0.465484, 0.360750, 0.279582,
0.216676, 0.167924, 0.130141, 0.100859, 0.078166
}, pow_0_625[10] = {
0.625000, 0.390625, 0.244141, 0.152588, 0.095367,
0.059605, 0.037253, 0.023283, 0.014552, 0.009095
};
float lpc_s[10], lpc_p[10], pole_out[170], zero_out[160];
int n;
for (n = 0; n < 10; n++) {
lpc_s[n] = lpc[n] * pow_0_625[n];
lpc_p[n] = lpc[n] * pow_0_775[n];
}
ff_celp_lp_zero_synthesis_filterf(zero_out, lpc_s,
q->formant_mem + 10, 160, 10);
memcpy(pole_out, q->postfilter_synth_mem, sizeof(float) * 10);
ff_celp_lp_synthesis_filterf(pole_out + 10, lpc_p, zero_out, 160, 10);
memcpy(q->postfilter_synth_mem, pole_out + 160, sizeof(float) * 10);
ff_tilt_compensation(&q->postfilter_tilt_mem, 0.3, pole_out + 10, 160);
ff_adaptive_gain_control(samples, pole_out + 10,
ff_dot_productf(q->formant_mem + 10, q->formant_mem + 10, 160),
160, 0.9375, &q->postfilter_agc_mem);
}
static int qcelp_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt)
{
@ -792,14 +828,14 @@ erasure:
10);
formant_mem += 40;
}
// postfilter, as per TIA/EIA/IS-733 2.4.8.6
postfilter(q, outbuffer, lpc);
memcpy(q->formant_mem, q->formant_mem + 160, 10 * sizeof(float));
// FIXME: postfilter and final gain control should be here.
// TIA/EIA/IS-733 2.4.8.6
formant_mem = q->formant_mem + 10;
for(i=0; i<160; i++)
*outbuffer++ = av_clipf(*formant_mem++, QCELP_CLIP_LOWER_BOUND,
outbuffer[i] = av_clipf(outbuffer[i], QCELP_CLIP_LOWER_BOUND,
QCELP_CLIP_UPPER_BOUND);
memcpy(q->prev_lspf, quantized_lspf, sizeof(q->prev_lspf));