[FFmpeg-cvslog] r15822 - in trunk/libavcodec: qcelpdata.h qcelpdec.c
vitor
subversion
Fri Nov 14 18:36:47 CET 2008
Author: vitor
Date: Fri Nov 14 18:36:47 2008
New Revision: 15822
Log:
More OKed parts of the QCELP decoder
patch by Kenan Gillet, kenan.gillet gmail com
Modified:
trunk/libavcodec/qcelpdata.h
trunk/libavcodec/qcelpdec.c
Modified: trunk/libavcodec/qcelpdata.h
==============================================================================
--- trunk/libavcodec/qcelpdata.h (original)
+++ trunk/libavcodec/qcelpdata.h Fri Nov 14 18:36:47 2008
@@ -461,6 +461,15 @@ static const int8_t qcelp_rate_half_code
#define QCELP_RATE_HALF_CODEBOOK_RATIO 0.5
/**
+ * sqrt(1.887) is the maximum of the pseudorandom
+ * white sequence used to generate the scaled codebook
+ * vector for framerate 1/4.
+ *
+ * TIA/EIA/IS-733 2.4.8.1.2
+ */
+#define QCELP_SQRT1887 1.373681186
+
+/**
* table for impulse response of BPF used to filter
* the white excitation for framerate 1/4 synthesis
*
Modified: trunk/libavcodec/qcelpdec.c
==============================================================================
--- trunk/libavcodec/qcelpdec.c (original)
+++ trunk/libavcodec/qcelpdec.c Fri Nov 14 18:36:47 2008
@@ -52,6 +52,144 @@ static void weighted_vector_sumf(float *
}
/**
+ * Initialize the speech codec according to the specification.
+ *
+ * TIA/EIA/IS-733 2.4.9
+ */
+static av_cold int qcelp_decode_init(AVCodecContext *avctx) {
+ QCELPContext *q = avctx->priv_data;
+ int i;
+
+ avctx->sample_fmt = SAMPLE_FMT_FLT;
+
+ for (i = 0; i < 10; i++)
+ q->prev_lspf[i] = (i + 1) / 11.;
+
+ return 0;
+}
+
+/**
+ * Computes the scaled codebook vector Cdn From INDEX and GAIN
+ * for all rates.
+ *
+ * The specification lacks some information here.
+ *
+ * TIA/EIA/IS-733 has an omission on the codebook index determination
+ * formula for RATE_FULL and RATE_HALF frames at section 2.4.8.1.1. It says
+ * you have to subtract the decoded index parameter from the given scaled
+ * codebook vector index 'n' to get the desired circular codebook index, but
+ * it does not mention that you have to clamp 'n' to [0-9] in order to get
+ * RI-compliant results.
+ *
+ * The reason for this mistake seems to be the fact they forgot to mention you
+ * have to do these calculations per codebook subframe and adjust given
+ * equation values accordingly.
+ *
+ * @param q the context
+ * @param gain array holding the 4 pitch subframe gain values
+ * @param cdn_vector array for the generated scaled codebook vector
+ */
+static void compute_svector(const QCELPContext *q,
+ const float *gain,
+ float *cdn_vector) {
+ int i, j, k;
+ uint16_t cbseed, cindex;
+ float *rnd, tmp_gain, fir_filter_value;
+
+ switch (q->framerate) {
+ case RATE_FULL:
+ for (i = 0; i < 16; i++) {
+ tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO;
+ cindex = -q->cindex[i];
+ for (j = 0; j < 10; j++)
+ *cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cindex++ & 127];
+ }
+ break;
+ case RATE_HALF:
+ for (i = 0; i < 4; i++) {
+ tmp_gain = gain[i] * QCELP_RATE_HALF_CODEBOOK_RATIO;
+ cindex = -q->cindex[i];
+ for (j = 0; j < 40; j++)
+ *cdn_vector++ = tmp_gain * qcelp_rate_half_codebook[cindex++ & 127];
+ }
+ break;
+ case RATE_QUARTER:
+ cbseed = (0x0003 & q->lspv[4])<<14 |
+ (0x003F & q->lspv[3])<< 8 |
+ (0x0060 & q->lspv[2])<< 1 |
+ (0x0007 & q->lspv[1])<< 3 |
+ (0x0038 & q->lspv[0])>> 3 ;
+ rnd = q->rnd_fir_filter_mem + 20;
+ for (i = 0; i < 8; i++) {
+ tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0);
+ for (k = 0; k < 20; k++) {
+ cbseed = 521 * cbseed + 259;
+ *rnd = (int16_t)cbseed;
+
+ // FIR filter
+ fir_filter_value = 0.0;
+ for (j = 0; j < 10; j++)
+ fir_filter_value += qcelp_rnd_fir_coefs[j ] * (rnd[-j ] + rnd[-20+j]);
+ fir_filter_value += qcelp_rnd_fir_coefs[10] * rnd[-10];
+
+ *cdn_vector++ = tmp_gain * fir_filter_value;
+ rnd++;
+ }
+ }
+ memcpy(q->rnd_fir_filter_mem, q->rnd_fir_filter_mem + 160, 20 * sizeof(float));
+ break;
+ case RATE_OCTAVE:
+ cbseed = q->first16bits;
+ for (i = 0; i < 8; i++) {
+ tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0);
+ for (j = 0; j < 20; j++) {
+ cbseed = 521 * cbseed + 259;
+ *cdn_vector++ = tmp_gain * (int16_t)cbseed;
+ }
+ }
+ break;
+ case I_F_Q:
+ cbseed = -44; // random codebook index
+ for (i = 0; i < 4; i++) {
+ tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO;
+ for (j = 0; j < 40; j++)
+ *cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cbseed++ & 127];
+ }
+ break;
+ }
+}
+
+/**
+ * Apply generic gain control.
+ *
+ * @param v_out output vector
+ * @param v_in gain-controlled vector
+ * @param v_ref vector to control gain of
+ *
+ * FIXME: If v_ref is a zero vector, it energy is zero
+ * and the behavior of the gain control is
+ * undefined in the specs.
+ *
+ * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
+ */
+static void apply_gain_ctrl(float *v_out,
+ const float *v_ref,
+ const float *v_in) {
+ int i, j, len;
+ float scalefactor;
+
+ for (i = 0, j = 0; i < 4; i++) {
+ scalefactor = ff_dot_productf(v_in + j, v_in + j, 40);
+ if (scalefactor)
+ scalefactor = sqrt(ff_dot_productf(v_ref + j, v_ref + j, 40) / scalefactor);
+ else
+ av_log_missing_feature(NULL, "Zero energy for gain control", 1);
+ for (len = j + 40; j < len; j++)
+ v_out[j] = scalefactor * v_in[j];
+ }
+}
+
+/**
* Apply filter in pitch-subframe steps.
*
* @param memory buffer for the previous state of the filter
@@ -131,9 +269,9 @@ void interpolate_lpc(QCELPContext *q,
if (weight != 1.0) {
weighted_vector_sumf(interpolated_lspf, curr_lspf, q->prev_lspf, weight, 1.0 - weight, 10);
- lspf2lpc(q, interpolated_lspf, lpc);
+ qcelp_lspf2lpc(interpolated_lspf, lpc);
} else if (q->framerate >= RATE_QUARTER || (q->framerate == I_F_Q && !subframe_num))
- lspf2lpc(q, curr_lspf, lpc);
+ qcelp_lspf2lpc(curr_lspf, lpc);
}
static int buf_size2framerate(const int buf_size) {
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