aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec
diff options
context:
space:
mode:
authorRonald S. Bultje <rsbultje@gmail.com>2010-04-21 17:50:08 +0000
committerRonald S. Bultje <rsbultje@gmail.com>2010-04-21 17:50:08 +0000
commit805a83d506ff28aa3690b85851519fcb52b06169 (patch)
tree952d128dcb381d31bab39433bbbc922b5eb2804d /libavcodec
parent5180a0b197457dd9ada538c0cd5e7470554dbfda (diff)
downloadffmpeg-805a83d506ff28aa3690b85851519fcb52b06169.tar.gz
Implement QCELP postfilter.
Originally committed as revision 22935 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/qcelpdec.c46
1 files changed, 41 insertions, 5 deletions
diff --git a/libavcodec/qcelpdec.c b/libavcodec/qcelpdec.c
index 707cb21e74..25ef324475 100644
--- a/libavcodec/qcelpdec.c
+++ b/libavcodec/qcelpdec.c
@@ -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;
}
- 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
+ // 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));
- 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));