From c681bd0480a8c6a99ff30e240ec52fe129f8eff9 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Fri, 2 Sep 2011 14:47:26 -0400
Subject: [PATCH] Improved mode/channel/bandwidth control mechanism
Now has tuning parameters for mono/stereo and voice/music. Also switches
to stereo during swb and without reducing the bandwidth.
---
src/opus_encoder.c | 168 +++++++++++++++++++++++++--------------------
src/test_opus.c | 12 ++++
2 files changed, 107 insertions(+), 73 deletions(-)
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index 02c3ef721..25baaa464 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -83,23 +83,43 @@ struct OpusEncoder {
int rangeFinal;
};
-/* Transition tables for the voice and audio modes. First column is the
+/* Transition tables for the voice and music. First column is the
middle (memoriless) threshold. The second column is the hysteresis
(difference with the middle) */
-static const int voice_bandwidth_thresholds[10] = {
+static const opus_int32 mono_voice_bandwidth_thresholds[8] = {
11000, 1000, /* NB<->MB */
14000, 1000, /* MB<->WB */
21000, 2000, /* WB<->SWB */
29000, 2000, /* SWB<->FB */
};
-static const int audio_bandwidth_thresholds[10] = {
- 30000, 0, /* MB not allowed */
- 20000, 2000, /* MB<->WB */
- 26000, 2000, /* WB<->SWB */
+static const opus_int32 mono_music_bandwidth_thresholds[8] = {
+ 14000, 1000, /* MB not allowed */
+ 18000, 2000, /* MB<->WB */
+ 24000, 2000, /* WB<->SWB */
33000, 2000, /* SWB<->FB */
};
-
-
+static const opus_int32 stereo_voice_bandwidth_thresholds[8] = {
+ 11000, 1000, /* NB<->MB */
+ 14000, 1000, /* MB<->WB */
+ 21000, 2000, /* WB<->SWB */
+ 32000, 2000, /* SWB<->FB */
+};
+static const opus_int32 stereo_music_bandwidth_thresholds[8] = {
+ 14000, 1000, /* MB not allowed */
+ 18000, 2000, /* MB<->WB */
+ 24000, 2000, /* WB<->SWB */
+ 48000, 2000, /* SWB<->FB */
+};
+/* Threshold bit-rates for switching between mono and stereo */
+static const opus_int32 stereo_voice_threshold = 26000;
+static const opus_int32 stereo_music_threshold = 36000;
+
+/* Threshold bit-rate for switching between SILK/hybrid and CELT-only */
+static const opus_int32 mode_thresholds[2][2] = {
+ /* voice */ /* music */
+ { 48000, 24000}, /* mono */
+ { 48000, 24000}, /* stereo */
+};
int opus_encoder_get_size(int channels)
{
int silkEncSizeBytes, celtEncSizeBytes;
@@ -173,7 +193,7 @@ int opus_encoder_init(OpusEncoder* st, int Fs, int channels, int application)
st->application = application;
st->signal_type = OPUS_SIGNAL_AUTO;
st->user_bandwidth = OPUS_BANDWIDTH_AUTO;
- st->voice_ratio = 90;
+ st->voice_ratio = -1;
st->encoder_buffer = st->Fs/100;
st->delay_compensation = st->Fs/400;
@@ -350,9 +370,10 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
VARDECL(opus_val16, pcm_buf);
int nb_compr_bytes;
int to_celt = 0;
- opus_int32 mono_rate;
opus_uint32 redundant_rng = 0;
int cutoff_Hz, hp_freq_smth1;
+ int voice_est;
+ opus_int32 equiv_rate;
ALLOC_STACK;
st->rangeFinal = 0;
@@ -370,41 +391,45 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
else
st->bitrate_bps = st->user_bitrate_bps;
+ /* Equivalent 20-ms rate for mode/channel/bandwidth decisions */
+ equiv_rate = st->bitrate_bps - 60*(st->Fs/frame_size - 50);
+
+ if (st->signal_type == OPUS_SIGNAL_VOICE)
+ voice_est = 127;
+ else if (st->signal_type == OPUS_SIGNAL_MUSIC)
+ voice_est = 0;
+ else if (st->voice_ratio >= 0)
+ voice_est = st->voice_ratio*327>>8;
+ else if (st->application == OPUS_APPLICATION_VOIP)
+ voice_est = 115;
+ else
+ voice_est = 64;
+
+#ifdef FUZZING
+ /* Random mono/stereo decision */
+ if (st->channels == 2 && (rand()&0x1F)==0)
+ st->stream_channels = 3-st->stream_channels;
+#else
/* Rate-dependent mono-stereo decision */
if (st->force_mono)
{
st->stream_channels = 1;
- } else if (st->mode == MODE_CELT_ONLY && st->channels == 2)
+ } else if (st->channels == 2)
{
- opus_int32 decision_rate;
- decision_rate = st->bitrate_bps + st->voice_ratio*st->voice_ratio;
- /* Add some hysteresis */
- if (st->stream_channels == 2)
- decision_rate += 4000;
- else
- decision_rate -= 4000;
- if (decision_rate>48000)
- st->stream_channels = 2;
- else
- st->stream_channels = 1;
+ opus_int32 stereo_threshold;
+ stereo_threshold = stereo_music_threshold + ((voice_est*voice_est*(stereo_voice_threshold-stereo_music_threshold))>>14);
+ if (st->stream_channels == 2)
+ stereo_threshold -= 4000;
+ else
+ stereo_threshold += 4000;
+ st->stream_channels = (equiv_rate > stereo_threshold) ? 2 : 1;
} else {
st->stream_channels = st->channels;
}
-
-#ifdef FUZZING
- if (st->channels == 2 && (rand()&0x1F)==0)
- st->stream_channels = 3-st->stream_channels;
#endif
- /* Equivalent bit-rate for mono */
- mono_rate = st->bitrate_bps;
- if (st->stream_channels==2)
- mono_rate = 2*mono_rate/3;
- /* Compensate for smaller frame sizes assuming an equivalent overhead
- of 60 bits/frame */
- mono_rate -= 60*(st->Fs/frame_size - 50);
-
#ifdef FUZZING
+ /* Random mode switching */
if ((rand()&0xF)==0)
{
if ((rand()&0x1)==0)
@@ -419,44 +444,26 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
}
#else
/* Mode selection depending on application and signal type */
- if (st->application==OPUS_APPLICATION_VOIP)
{
- opus_int32 threshold;
- threshold = 20000;
- /* OPUS_APPLICATION_VOIP default to auto high-pass */
- /* Hysteresis */
- if (st->prev_mode == MODE_CELT_ONLY)
- threshold -= 4000;
- else if (st->prev_mode>0)
- threshold += 4000;
-
- /* OPUS_APPLICATION_VOIP defaults to MODE_SILK_ONLY */
- if (st->signal_type == OPUS_SIGNAL_MUSIC && mono_rate > threshold)
- st->mode = MODE_CELT_ONLY;
- else
- st->mode = MODE_SILK_ONLY;
- } else {/* OPUS_APPLICATION_AUDIO */
- opus_int32 threshold;
- /* SILK/CELT threshold is higher for voice than for music */
- threshold = 36000;
- /* OPUS_APPLICATION_AUDIO disables the high-pass */
- if (st->signal_type == OPUS_SIGNAL_MUSIC)
- threshold -= 20000;
- else if (st->signal_type == OPUS_SIGNAL_VOICE)
- threshold += 8000;
-
- /* Hysteresis */
- if (st->prev_mode == MODE_CELT_ONLY)
- threshold -= 4000;
- else if (st->prev_mode>0)
- threshold += 4000;
-
- if (mono_rate>threshold)
- st->mode = MODE_CELT_ONLY;
- else
- st->mode = MODE_SILK_ONLY;
+ int chan;
+ opus_int32 mode_voice, mode_music;
+ opus_int32 threshold;
+
+ chan = (st->channels==2) && !st->force_mono;
+ mode_voice = mode_thresholds[chan][0];
+ mode_music = mode_thresholds[chan][1];
+ threshold = mode_music + ((voice_est*voice_est*(mode_voice-mode_music))>>14);
+
+ /* Hysteresis */
+ if (st->prev_mode == MODE_CELT_ONLY)
+ threshold -= 4000;
+ else if (st->prev_mode>0)
+ threshold += 4000;
+
+ st->mode = (equiv_rate >= threshold) ? MODE_CELT_ONLY: MODE_SILK_ONLY;
}
#endif
+
/* Override the chosen mode to make sure we meet the requested frame size */
if (st->mode == MODE_CELT_ONLY && frame_size > st->Fs/50)
st->mode = MODE_SILK_ONLY;
@@ -491,10 +498,24 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
/* Automatic (rate-dependent) bandwidth selection */
if (st->mode == MODE_CELT_ONLY || st->first || st->silk_mode.allowBandwidthSwitch)
{
- const int *bandwidth_thresholds;
+ const opus_int32 *voice_bandwidth_thresholds, *music_bandwidth_thresholds;
+ opus_int32 bandwidth_thresholds[8];
int bandwidth = OPUS_BANDWIDTH_FULLBAND;
- bandwidth_thresholds = st->mode == MODE_CELT_ONLY ? audio_bandwidth_thresholds : voice_bandwidth_thresholds;
+ if (st->channels==2 && !st->force_mono)
+ {
+ voice_bandwidth_thresholds = stereo_voice_bandwidth_thresholds;
+ music_bandwidth_thresholds = stereo_music_bandwidth_thresholds;
+ } else {
+ voice_bandwidth_thresholds = mono_voice_bandwidth_thresholds;
+ music_bandwidth_thresholds = mono_music_bandwidth_thresholds;
+ }
+ /* Interpolate bandwidth thresholds depending on voice estimation */
+ for (i=0;i<8;i++)
+ {
+ bandwidth_thresholds[i] = music_bandwidth_thresholds[i]
+ + ((voice_est*voice_est*(voice_bandwidth_thresholds[i]-music_bandwidth_thresholds[i]))>>14);
+ }
do {
int threshold, hysteresis;
threshold = bandwidth_thresholds[2*(bandwidth-OPUS_BANDWIDTH_MEDIUMBAND)];
@@ -506,7 +527,7 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
else
threshold += hysteresis;
}
- if (mono_rate >= threshold)
+ if (equiv_rate >= threshold)
break;
} while (--bandwidth>OPUS_BANDWIDTH_NARROWBAND);
st->bandwidth = bandwidth;
@@ -545,6 +566,7 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
if (st->mode == MODE_HYBRID && st->bandwidth <= OPUS_BANDWIDTH_WIDEBAND)
st->mode = MODE_SILK_ONLY;
+ /* printf("%d %d %d %d\n", st->bitrate_bps, st->stream_channels, st->mode, st->bandwidth); */
bytes_target = st->bitrate_bps * frame_size / (st->Fs * 8) - 1;
data += 1;
@@ -1040,7 +1062,7 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
case OPUS_SET_VOICE_RATIO_REQUEST:
{
opus_int32 value = va_arg(ap, opus_int32);
- if (value>100 || value<0)
+ if (value>100 || value<-1)
goto bad_arg;
st->voice_ratio = value;
}
diff --git a/src/test_opus.c b/src/test_opus.c
index 7ec1e0593..62af93ec5 100644
--- a/src/test_opus.c
+++ b/src/test_opus.c
@@ -116,6 +116,7 @@ int main(int argc, char *argv[])
int encode_only=0, decode_only=0;
int max_frame_size = 960*6;
int curr_read=0;
+ int sweep_bps = 0;
if (argc < 7 )
{
@@ -223,6 +224,9 @@ int main(int argc, char *argv[])
} else if( STR_CASEINSENSITIVE_COMPARE( argv[ args ], "-loss" ) == 0 ) {
packet_loss_perc = atoi( argv[ args + 1 ] );
args += 2;
+ } else if( STR_CASEINSENSITIVE_COMPARE( argv[ args ], "-sweep" ) == 0 ) {
+ sweep_bps = atoi( argv[ args + 1 ] );
+ args += 2;
} else {
printf( "Error: unrecognized setting: %s\n\n", argv[ args ] );
print_usage( argv );
@@ -363,6 +367,14 @@ int main(int argc, char *argv[])
}
len[toggle] = opus_encode(enc, in, frame_size, data[toggle], max_payload_bytes);
+ if (sweep_bps!=0)
+ {
+ bitrate_bps += sweep_bps;
+ /* safety */
+ if (bitrate_bps<1000)
+ bitrate_bps = 1000;
+ opus_encoder_ctl(enc, OPUS_SET_BITRATE(bitrate_bps));
+ }
opus_encoder_ctl(enc, OPUS_GET_FINAL_RANGE(&enc_final_range[toggle]));
if (len[toggle] < 0)
{
--
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