From a20545781e2541ea3bbdee5ef33fabcba20b1dc1 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Fri, 25 Nov 2011 23:07:46 -0500
Subject: [PATCH] Adds automatic bandwidth detection
Haven't tested it much and not sure not to use it without risk
for high-quality streams that may change bandwidth
---
src/analysis.c | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/src/analysis.c b/src/analysis.c
index 8f2971e49..56710b4f3 100644
--- a/src/analysis.c
+++ b/src/analysis.c
@@ -80,6 +80,7 @@ typedef struct {
float prev_tonality;
float E[NB_FRAMES][NB_TBANDS];
float lowE[NB_TBANDS], highE[NB_TBANDS];
+ float meanE[NB_TBANDS], meanRE[NB_TBANDS];
float mem[32];
float cmean[8];
float std[9];
@@ -90,6 +91,7 @@ typedef struct {
int last_music;
int last_transition;
int count;
+ int opus_bandwidth;
} TonalityAnalysisState;
void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEncoder *celt_enc, const opus_val16 *x, int C)
@@ -115,13 +117,17 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEnc
float frame_stationarity;
float relativeE;
float frame_prob;
- float alpha, alphaE;
+ float alpha, alphaE, alphaE2;
float frame_loudness;
+ float bandwidth_mask;
+ int bandwidth=0;
+ float bandE[NB_TBANDS];
celt_encoder_ctl(celt_enc, CELT_GET_MODE(&mode));
tonal->last_transition++;
alpha = 1.f/IMIN(20, 1+tonal->count);
alphaE = 1.f/IMIN(50, 1+tonal->count);
+ alphaE2 = 1.f/IMIN(6000, 1+tonal->count);
if (tonal->count<4)
tonal->music_prob = .5;
@@ -201,6 +207,7 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEnc
info->boost_amount[0]=info->boost_amount[1]=0;
info->boost_band[0]=info->boost_band[1]=0;
frame_loudness = 0;
+ bandwidth_mask = 0;
for (b=0;b<NB_TBANDS;b++)
{
float E=0, tE=0, nE=0;
@@ -214,11 +221,19 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEnc
tE += binE*tonality[i];
nE += binE*2*(.5-noisiness[i]);
}
+ bandE[b] = E;
tonal->E[tonal->E_count][b] = E;
frame_noisiness += nE/(1e-15+E);
frame_loudness += sqrt(E+1e-10);
/* Add a reasonable noise floor */
+ tonal->meanE[b] = (1-alphaE2)*tonal->meanE[b] + alphaE2*E;
+ tonal->meanRE[b] = (1-alphaE2)*tonal->meanRE[b] + alphaE2*sqrt(E);
+ /* 13 dB slope for spreading function */
+ bandwidth_mask = MAX32(.05*bandwidth_mask, E);
+ /* Checks if band looks like stationary noise or if it's below a (trivial) masking curve */
+ if (tonal->meanRE[b]*tonal->meanRE[b] < tonal->meanE[b]*.95 && E>.1*bandwidth_mask)
+ bandwidth = b;
logE[b] = log(E+1e-10);
tonal->lowE[b] = MIN32(logE[b], tonal->lowE[b]+.01);
tonal->highE[b] = MAX32(logE[b], tonal->highE[b]-.1);
@@ -260,6 +275,7 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEnc
}
tonal->prev_band_tonality[b] = band_tonality[b];
}
+
frame_loudness = 20*log10(frame_loudness);
tonal->Etracker = MAX32(tonal->Etracker-.03, frame_loudness);
tonal->lowECount *= (1-alphaE);
@@ -369,5 +385,20 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEnc
printf("%f ", features[i]);
printf("\n");*/
+ /* FIXME: Can't detect SWB for now because the last band ends at 12 kHz */
+ if (bandwidth == NB_TBANDS-1 || tonal->count<100)
+ {
+ tonal->opus_bandwidth = OPUS_BANDWIDTH_FULLBAND;
+ } else {
+ int close_enough = 0;
+ if (bandE[bandwidth-1] < 3000*bandE[NB_TBANDS-1] && bandwidth < NB_TBANDS-1)
+ close_enough=1;
+ if (bandwidth<=11 || (bandwidth==12 && close_enough))
+ tonal->opus_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
+ else if (bandwidth<=13)
+ tonal->opus_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
+ else if (bandwidth<=15 || (bandwidth==16 && close_enough))
+ tonal->opus_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
+ }
info->valid = 1;
}
--
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