From b08c4ca3f54c964f1108170d0e4b7df2200b6a82 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Fri, 26 Apr 2013 16:32:10 -0400
Subject: [PATCH] Surround: Better LFE handling
Forces CELT-only mode for LFE (despite the rate) and "locks" most of the
CELT analysis:
- No transient or TF
- Band boost on first band
- Only first two bands get PVQ bits
- Forced energy decay after the first two bands
---
celt/celt.h | 2 +-
celt/celt_encoder.c | 29 ++++++++++++++++++++++-------
celt/quant_bands.c | 14 +++++++++-----
celt/quant_bands.h | 2 +-
src/opus_encoder.c | 13 +++++++++++++
src/opus_multistream_encoder.c | 4 ++--
6 files changed, 48 insertions(+), 16 deletions(-)
diff --git a/celt/celt.h b/celt/celt.h
index a1c2c4805..a8f7cb036 100644
--- a/celt/celt.h
+++ b/celt/celt.h
@@ -107,7 +107,7 @@ typedef struct {
#define CELT_SET_ANALYSIS_REQUEST 10022
#define CELT_SET_ANALYSIS(x) CELT_SET_ANALYSIS_REQUEST, __celt_check_analysis_ptr(x)
-#define OPUS_SET_LFE_REQUEST 10022
+#define OPUS_SET_LFE_REQUEST 10024
#define OPUS_SET_LFE(x) OPUS_SET_LFE_REQUEST, __opus_check_int(x)
/* Encoder stuff */
diff --git a/celt/celt_encoder.c b/celt/celt_encoder.c
index 7347cb315..a88e59228 100644
--- a/celt/celt_encoder.c
+++ b/celt/celt_encoder.c
@@ -74,6 +74,7 @@ struct OpusCustomEncoder {
int loss_rate;
int lsb_depth;
int variable_duration;
+ int lfe;
/* Everything beyond this point gets cleared on a reset */
#define ENCODER_RESET_START rng
@@ -869,7 +870,7 @@ static int stereo_analysis(const CELTMode *m, const celt_norm *X,
static opus_val16 dynalloc_analysis(const opus_val16 *bandLogE, const opus_val16 *bandLogE2,
int nbEBands, int start, int end, int C, int *offsets, int lsb_depth, const opus_int16 *logN,
int isTransient, int vbr, int constrained_vbr, const opus_int16 *eBands, int LM,
- int effectiveBytes, opus_int32 *tot_boost_)
+ int effectiveBytes, opus_int32 *tot_boost_, int lfe)
{
int i, c;
opus_int32 tot_boost=0;
@@ -897,7 +898,7 @@ static opus_val16 dynalloc_analysis(const opus_val16 *bandLogE, const opus_val16
maxDepth = MAX16(maxDepth, bandLogE[c*nbEBands+i]-noise_floor[i]);
} while (++c<C);
/* Make sure that dynamic allocation can't make us bust the budget */
- if (effectiveBytes > 50 && LM>=1)
+ if (effectiveBytes > 50 && LM>=1 && !lfe)
{
int last=0;
c=0;do
@@ -1356,7 +1357,7 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
isTransient = 0;
shortBlocks = 0;
- if (st->complexity >= 1)
+ if (st->complexity >= 1 && !st->lfe)
{
isTransient = transient_analysis(in, N+st->overlap, CC,
&tf_estimate, &tf_chan);
@@ -1429,7 +1430,7 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
ALLOC(tf_res, nbEBands, int);
/* Disable variable tf resolution for hybrid and at very low bitrate */
- if (effectiveBytes>=15*C && st->start==0 && st->complexity>=2)
+ if (effectiveBytes>=15*C && st->start==0 && st->complexity>=2 && !st->lfe)
{
int lambda;
if (effectiveBytes<40)
@@ -1455,7 +1456,7 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
quant_coarse_energy(mode, st->start, st->end, effEnd, bandLogE,
oldBandE, total_bits, error, enc,
C, LM, nbAvailableBytes, st->force_intra,
- &st->delayedIntra, st->complexity >= 4, st->loss_rate);
+ &st->delayedIntra, st->complexity >= 4, st->loss_rate, st->lfe);
tf_encode(st->start, st->end, isTransient, tf_res, LM, tf_select, enc);
@@ -1494,7 +1495,10 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
maxDepth = dynalloc_analysis(bandLogE, bandLogE2, nbEBands, st->start, st->end, C, offsets,
st->lsb_depth, mode->logN, isTransient, st->vbr, st->constrained_vbr,
- eBands, LM, effectiveBytes, &tot_boost);
+ eBands, LM, effectiveBytes, &tot_boost, st->lfe);
+ /* For LFE, everything interesting is in the first band */
+ if (st->lfe)
+ offsets[0] = IMIN(8, effectiveBytes/3);
ALLOC(cap, nbEBands, int);
init_caps(mode,cap,LM,C);
@@ -1560,7 +1564,10 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
alloc_trim = 5;
if (tell+(6<<BITRES) <= total_bits - total_boost)
{
- alloc_trim = alloc_trim_analysis(mode, X, bandLogE,
+ if (st->lfe)
+ alloc_trim = 5;
+ else
+ alloc_trim = alloc_trim_analysis(mode, X, bandLogE,
st->end, LM, C, N, &st->analysis, &st->stereo_saving, tf_estimate, st->intensity);
ec_enc_icdf(enc, alloc_trim, trim_icdf, 7);
tell = ec_tell_frac(enc);
@@ -1738,6 +1745,8 @@ int celt_encode_with_ec(CELTEncoder * OPUS_RESTRICT st, const opus_val16 * pcm,
if (st->analysis.valid)
signalBandwidth = st->analysis.bandwidth;
#endif
+ if (st->lfe)
+ signalBandwidth = 1;
codedBands = compute_allocation(mode, st->start, st->end, offsets, cap,
alloc_trim, &st->intensity, &dual_stereo, bits, &balance, pulses,
fine_quant, fine_priority, C, LM, enc, 1, st->lastCodedBands, signalBandwidth);
@@ -2127,6 +2136,12 @@ int opus_custom_encoder_ctl(CELTEncoder * OPUS_RESTRICT st, int request, ...)
*value=st->rng;
}
break;
+ case OPUS_SET_LFE_REQUEST:
+ {
+ opus_int32 value = va_arg(ap, opus_int32);
+ st->lfe = value;
+ }
+ break;
default:
goto bad_request;
}
diff --git a/celt/quant_bands.c b/celt/quant_bands.c
index 514f03c42..48196bde3 100644
--- a/celt/quant_bands.c
+++ b/celt/quant_bands.c
@@ -157,7 +157,7 @@ static int quant_coarse_energy_impl(const CELTMode *m, int start, int end,
const opus_val16 *eBands, opus_val16 *oldEBands,
opus_int32 budget, opus_int32 tell,
const unsigned char *prob_model, opus_val16 *error, ec_enc *enc,
- int C, int LM, int intra, opus_val16 max_decay)
+ int C, int LM, int intra, opus_val16 max_decay, int lfe)
{
int i, c;
int badness = 0;
@@ -222,6 +222,8 @@ static int quant_coarse_energy_impl(const CELTMode *m, int start, int end,
if (bits_left < 16)
qi = IMAX(-1, qi);
}
+ if (lfe && i>=2)
+ qi = IMIN(qi, 0);
if (budget-tell >= 15)
{
int pi;
@@ -253,13 +255,13 @@ static int quant_coarse_energy_impl(const CELTMode *m, int start, int end,
prev[c] = prev[c] + SHL32(q,7) - MULT16_16(beta,PSHR32(q,8));
} while (++c < C);
}
- return badness;
+ return lfe ? 0 : badness;
}
void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
const opus_val16 *eBands, opus_val16 *oldEBands, opus_uint32 budget,
opus_val16 *error, ec_enc *enc, int C, int LM, int nbAvailableBytes,
- int force_intra, opus_val32 *delayedIntra, int two_pass, int loss_rate)
+ int force_intra, opus_val32 *delayedIntra, int two_pass, int loss_rate, int lfe)
{
int intra;
opus_val16 max_decay;
@@ -289,6 +291,8 @@ void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
max_decay = MIN32(max_decay, .125f*nbAvailableBytes);
#endif
}
+ if (lfe)
+ max_decay=3;
enc_start_state = *enc;
ALLOC(oldEBands_intra, C*m->nbEBands, opus_val16);
@@ -298,7 +302,7 @@ void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
if (two_pass || intra)
{
badness1 = quant_coarse_energy_impl(m, start, end, eBands, oldEBands_intra, budget,
- tell, e_prob_model[LM][1], error_intra, enc, C, LM, 1, max_decay);
+ tell, e_prob_model[LM][1], error_intra, enc, C, LM, 1, max_decay, lfe);
}
if (!intra)
@@ -325,7 +329,7 @@ void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
*enc = enc_start_state;
badness2 = quant_coarse_energy_impl(m, start, end, eBands, oldEBands, budget,
- tell, e_prob_model[LM][intra], error, enc, C, LM, 0, max_decay);
+ tell, e_prob_model[LM][intra], error, enc, C, LM, 0, max_decay, lfe);
if (two_pass && (badness1 < badness2 || (badness1 == badness2 && ((opus_int32)ec_tell_frac(enc))+intra_bias > tell_intra)))
{
diff --git a/celt/quant_bands.h b/celt/quant_bands.h
index b3187fada..0490bca4b 100644
--- a/celt/quant_bands.h
+++ b/celt/quant_bands.h
@@ -51,7 +51,7 @@ void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
const opus_val16 *eBands, opus_val16 *oldEBands, opus_uint32 budget,
opus_val16 *error, ec_enc *enc, int C, int LM,
int nbAvailableBytes, int force_intra, opus_val32 *delayedIntra,
- int two_pass, int loss_rate);
+ int two_pass, int loss_rate, int lfe);
void quant_fine_energy(const CELTMode *m, int start, int end, opus_val16 *oldEBands, opus_val16 *error, int *fine_quant, ec_enc *enc, int C);
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index 88bf5aff8..235f5573b 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -78,6 +78,7 @@ struct OpusEncoder {
opus_int32 user_bitrate_bps;
int lsb_depth;
int encoder_buffer;
+ int lfe;
#define OPUS_ENCODER_RESET_START stream_channels
int stream_channels;
@@ -1234,6 +1235,11 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
/* CELT mode doesn't support mediumband, use wideband instead */
if (st->mode == MODE_CELT_ONLY && st->bandwidth == OPUS_BANDWIDTH_MEDIUMBAND)
st->bandwidth = OPUS_BANDWIDTH_WIDEBAND;
+ if (st->lfe)
+ {
+ st->bandwidth = OPUS_BANDWIDTH_NARROWBAND;
+ st->mode = MODE_CELT_ONLY;
+ }
/* Can't support higher than wideband for >20 ms frames */
if (frame_size > st->Fs/50 && (st->mode == MODE_CELT_ONLY || st->bandwidth > OPUS_BANDWIDTH_WIDEBAND))
@@ -2203,6 +2209,13 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
st->user_forced_mode = value;
}
break;
+ case OPUS_SET_LFE_REQUEST:
+ {
+ opus_int32 value = va_arg(ap, opus_int32);
+ st->lfe = value;
+ celt_encoder_ctl(celt_enc, OPUS_SET_LFE(value));
+ }
+ break;
case CELT_GET_MODE_REQUEST:
{
diff --git a/src/opus_multistream_encoder.c b/src/opus_multistream_encoder.c
index b3e0ccc4a..9dcbb71c6 100644
--- a/src/opus_multistream_encoder.c
+++ b/src/opus_multistream_encoder.c
@@ -329,7 +329,7 @@ static void surround_rate_allocation(
int total = ((st->layout.nb_streams-st->layout.nb_coupled_streams-(st->lfe_stream!=-1))<<8) /* mono */
+ coupled_ratio*st->layout.nb_coupled_streams /* stereo */
+ (st->lfe_stream!=-1)*lfe_ratio;
- channel_rate = 256*st->bitrate_bps/total;
+ channel_rate = 256*(st->bitrate_bps-2000)/total;
}
#ifndef FIXED_POINT
if (st->variable_duration==OPUS_FRAMESIZE_VARIABLE && frame_size != Fs/50)
@@ -347,7 +347,7 @@ static void surround_rate_allocation(
else if (i!=st->lfe_stream)
rate[i] = channel_rate;
else
- rate[i] = channel_rate*lfe_ratio>>8;
+ rate[i] = 2000+(channel_rate*lfe_ratio>>8);
}
--
GitLab