eden-emu/opus
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This commit is contained in:
Jean-Marc Valin 2011-05-03 17:06:54 -04:00
parent 0734cad597
commit 243ff0c63b
1 changed files with 10 additions and 2 deletions
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12
src/opus_encoder.c
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@ -118,10 +118,12 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
int to_celt = 0; int to_celt = 0;
celt_int32 mono_rate; celt_int32 mono_rate;
/* Rete-dependent mono-stereo decision */
if (st->channels == 2) if (st->channels == 2)
{ {
celt_int32 decision_rate; celt_int32 decision_rate;
decision_rate = st->bitrate_bps + st->voice_ratio*st->voice_ratio; decision_rate = st->bitrate_bps + st->voice_ratio*st->voice_ratio;
/* Add some hysteresis */
if (st->stream_channels == 2) if (st->stream_channels == 2)
decision_rate += 4000; decision_rate += 4000;
else else
@ -145,7 +147,9 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
if (st->user_mode==OPUS_MODE_AUTO) if (st->user_mode==OPUS_MODE_AUTO)
{ {
celt_int32 decision_rate; celt_int32 decision_rate;
/* SILK/CELT threshold is higher for voice than for music */
decision_rate = mono_rate - 3*st->voice_ratio*st->voice_ratio; decision_rate = mono_rate - 3*st->voice_ratio*st->voice_ratio;
/* Hysteresis */
if (st->prev_mode == MODE_CELT_ONLY) if (st->prev_mode == MODE_CELT_ONLY)
decision_rate += 4000; decision_rate += 4000;
else if (st->prev_mode>0) else if (st->prev_mode>0)
@ -161,7 +165,7 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
st->mode = MODE_CELT_ONLY; st->mode = MODE_CELT_ONLY;
} }
/* Bandwidth selection */ /* Automatic (rate-dependent) bandwidth selection */
if (st->mode == MODE_CELT_ONLY) if (st->mode == MODE_CELT_ONLY)
{ {
if (mono_rate>35000 || (mono_rate>28000 && st->bandwidth==BANDWIDTH_FULLBAND)) if (mono_rate>35000 || (mono_rate>28000 && st->bandwidth==BANDWIDTH_FULLBAND))
@ -184,10 +188,14 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
st->bandwidth = BANDWIDTH_MEDIUMBAND; st->bandwidth = BANDWIDTH_MEDIUMBAND;
else else
st->bandwidth = BANDWIDTH_NARROWBAND; st->bandwidth = BANDWIDTH_NARROWBAND;
/* Prevents any transition to SWB/FB until the SILK layer has fully
switched to WB mode and turned the variable LP filter off */
if (!st->silk_mode.inWBmodeWithoutVariableLP && st->bandwidth > BANDWIDTH_WIDEBAND) if (!st->silk_mode.inWBmodeWithoutVariableLP && st->bandwidth > BANDWIDTH_WIDEBAND)
st->bandwidth = BANDWIDTH_WIDEBAND; st->bandwidth = BANDWIDTH_WIDEBAND;
} }
/* Prevents Opus from wasting bits on frequencies that are above
the Nyquist rate of the input signal */
if (st->Fs <= 24000 && st->bandwidth > BANDWIDTH_SUPERWIDEBAND) if (st->Fs <= 24000 && st->bandwidth > BANDWIDTH_SUPERWIDEBAND)
st->bandwidth = BANDWIDTH_SUPERWIDEBAND; st->bandwidth = BANDWIDTH_SUPERWIDEBAND;
if (st->Fs <= 16000 && st->bandwidth > BANDWIDTH_WIDEBAND) if (st->Fs <= 16000 && st->bandwidth > BANDWIDTH_WIDEBAND)
@ -200,7 +208,7 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
if (st->user_bandwidth != BANDWIDTH_AUTO) if (st->user_bandwidth != BANDWIDTH_AUTO)
st->bandwidth = st->user_bandwidth; st->bandwidth = st->user_bandwidth;
/* Preventing non-sensical configurations */ /* Prevents nonsensical configurations, i.e. modes that don't exist */
if (frame_size < st->Fs/100 && st->mode != MODE_CELT_ONLY) if (frame_size < st->Fs/100 && st->mode != MODE_CELT_ONLY)
st->mode = MODE_CELT_ONLY; st->mode = MODE_CELT_ONLY;
if (frame_size > st->Fs/50 && st->mode != MODE_SILK_ONLY) if (frame_size > st->Fs/50 && st->mode != MODE_SILK_ONLY)