Synthesis filter
This commit is contained in:

committed by
Michael Niedermayer

parent
4920a1a913
commit
b7c7fc3359
@@ -34,6 +34,7 @@
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#include "g729.h"
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#include "g729.h"
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#include "lsp.h"
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#include "lsp.h"
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#include "celp_math.h"
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#include "celp_math.h"
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#include "celp_filters.h"
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#include "acelp_filters.h"
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#include "acelp_filters.h"
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#include "acelp_pitch_delay.h"
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#include "acelp_pitch_delay.h"
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#include "acelp_vectors.h"
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#include "acelp_vectors.h"
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@@ -57,6 +58,9 @@
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*/
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*/
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#define LSFQ_DIFF_MIN 321
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#define LSFQ_DIFF_MIN 321
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/// interpolation filter length
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#define INTERPOL_LEN 11
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/**
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/**
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* minimum gain pitch value (3.8, Equation 47)
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* minimum gain pitch value (3.8, Equation 47)
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* 0.2 in (1.14)
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* 0.2 in (1.14)
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@@ -111,6 +115,9 @@ typedef struct {
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int16_t quant_energy[4]; ///< (5.10) past quantized energy
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int16_t quant_energy[4]; ///< (5.10) past quantized energy
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/// previous speech data for LP synthesis filter
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int16_t syn_filter_data[10];
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/// (1.14) pitch gain of current and five previous subframes
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/// (1.14) pitch gain of current and five previous subframes
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int16_t past_gain_pitch[6];
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int16_t past_gain_pitch[6];
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@@ -283,6 +290,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
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int pitch_delay_int; // pitch delay, integer part
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int pitch_delay_int; // pitch delay, integer part
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int pitch_delay_3x; // pitch delay, multiplied by 3
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int pitch_delay_3x; // pitch delay, multiplied by 3
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int16_t fc[SUBFRAME_SIZE]; // fixed-codebook vector
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int16_t fc[SUBFRAME_SIZE]; // fixed-codebook vector
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int16_t synth[SUBFRAME_SIZE+10]; // fixed-codebook vector
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int j;
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int is_periodic = 0; // whether one of the subframes is declared as periodic or not
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int is_periodic = 0; // whether one of the subframes is declared as periodic or not
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if (*data_size < SUBFRAME_SIZE << 2) {
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if (*data_size < SUBFRAME_SIZE << 2) {
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@@ -476,10 +485,42 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
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( ctx->was_periodic && frame_erasure) ? 0 : ctx->past_gain_code[0],
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( ctx->was_periodic && frame_erasure) ? 0 : ctx->past_gain_code[0],
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1 << 13, 14, SUBFRAME_SIZE);
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1 << 13, 14, SUBFRAME_SIZE);
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memcpy(synth, ctx->syn_filter_data, 10 * sizeof(int16_t));
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/* Temporary synth buffer is required since filter needs additional space at top of buffer and, thus,
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synthesis can not be done directly to output buffer. This buffer will be reused by future
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postprocessing filters. */
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if (ff_celp_lp_synthesis_filter(
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synth+10,
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&lp[i][1],
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ctx->exc + i * SUBFRAME_SIZE,
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SUBFRAME_SIZE,
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10,
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1,
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0x800)) {
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/* Overflow occured, downscale excitation signal... */
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for (j = 0; j < 2 * SUBFRAME_SIZE + PITCH_DELAY_MAX + INTERPOL_LEN; j++)
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ctx->exc_base[j] >>= 2;
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ff_celp_lp_synthesis_filter(
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synth+10,
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&lp[i][1],
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ctx->exc + i * SUBFRAME_SIZE,
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SUBFRAME_SIZE,
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10,
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0,
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0x800);
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}
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/* Save data (without postfilter) for use in next subframe. */
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memcpy(ctx->syn_filter_data, synth+SUBFRAME_SIZE, 10 * sizeof(int16_t));
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if (frame_erasure)
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if (frame_erasure)
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ctx->pitch_delay_int_prev = FFMIN(ctx->pitch_delay_int_prev + 1, PITCH_DELAY_MAX);
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ctx->pitch_delay_int_prev = FFMIN(ctx->pitch_delay_int_prev + 1, PITCH_DELAY_MAX);
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else
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else
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ctx->pitch_delay_int_prev = pitch_delay_int;
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ctx->pitch_delay_int_prev = pitch_delay_int;
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/* Dumb. Will be replaced by high-pass filter */
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memcpy(out_frame + i * SUBFRAME_SIZE, synth + 10, SUBFRAME_SIZE * sizeof(int16_t));
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}
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}
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ctx->was_periodic = is_periodic;
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ctx->was_periodic = is_periodic;
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