ref: 6b45974fbd3bd8a50f9532680cb89590e150a843
parent: ff16ab098e1ffe799f8ea87efc7458fcf0a93371
author: Jean-Marc Valin <[email protected]>
date: Thu Sep 20 18:00:22 EDT 2012
Reduces rate/max rate to make room for redundancy This fixes a problem where we could end up starving the redundancy frame, especially for CBR. The solution is to make sure that some bits are left available -- assuming we use the same rate for redundancy as for the rest of the frame.
--- a/silk/control_audio_bandwidth.c
+++ b/silk/control_audio_bandwidth.c
@@ -80,6 +80,8 @@
} else { if( psEncC->sLP.transition_frame_no <= 0 ) {encControl->switchReady = 1;
+ /* Make room for redundancy */
+ encControl->maxBits -= encControl->maxBits * 5 / ( encControl->payloadSize_ms + 5 );
} else {/* Direction: down (at double speed) */
psEncC->sLP.mode = -2;
@@ -106,6 +108,8 @@
} else { if( psEncC->sLP.mode == 0 ) {encControl->switchReady = 1;
+ /* Make room for redundancy */
+ encControl->maxBits -= encControl->maxBits * 5 / ( encControl->payloadSize_ms + 5 );
} else {/* Direction: up */
psEncC->sLP.mode = 1;
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -458,7 +458,7 @@
int prefill=0;
int start_band = 0;
int redundancy = 0;
- int redundancy_bytes = 0;
+ int redundancy_bytes = 0; /* Number of bytes to use for redundancy frame */
int celt_to_silk = 0;
VARDECL(opus_val16, pcm_buf);
int nb_compr_bytes;
@@ -465,13 +465,13 @@
int to_celt = 0;
opus_uint32 redundant_rng = 0;
int cutoff_Hz, hp_freq_smth1;
- int voice_est;
+ int voice_est; /* Probability of voice in Q7 */
opus_int32 equiv_rate;
int delay_compensation;
int frame_rate;
- opus_int32 max_rate;
+ opus_int32 max_rate; /* Max bitrate we're allowed to use */
int curr_bandwidth;
- opus_int32 max_data_bytes;
+ opus_int32 max_data_bytes; /* Max number of bytes we're allowed to use */
VARDECL(opus_val16, tmp_prefill);
ALLOC_STACK;
@@ -652,6 +652,7 @@
}
}
}
+ /* For the first frame at a new SILK bandwidth */
if (st->silk_bw_switch)
{redundancy = 1;
@@ -659,6 +660,15 @@
st->silk_bw_switch = 0;
}
+ if (redundancy)
+ {+ /* Fair share of the max size allowed */
+ redundancy_bytes = IMIN(257, max_data_bytes*(opus_int32)(st->Fs/200)/(frame_size+st->Fs/200));
+ /* For VBR, target the actual bitrate (subject to the limit above) */
+ if (st->use_vbr)
+ redundancy_bytes = IMIN(redundancy_bytes, st->bitrate_bps/1600);
+ }
+
if (st->mode != MODE_CELT_ONLY && st->prev_mode == MODE_CELT_ONLY)
{silk_EncControlStruct dummy;
@@ -823,7 +833,7 @@
st->mode = MODE_SILK_ONLY;
/* printf("%d %d %d %d\n", st->bitrate_bps, st->stream_channels, st->mode, curr_bandwidth); */- bytes_target = IMIN(max_data_bytes, st->bitrate_bps * frame_size / (st->Fs * 8)) - 1;
+ bytes_target = IMIN(max_data_bytes-redundancy_bytes, st->bitrate_bps * frame_size / (st->Fs * 8)) - 1;
data += 1;
@@ -929,7 +939,7 @@
st->silk_mode.useCBR = !st->use_vbr;
/* Call SILK encoder for the low band */
- nBytes = IMIN(1275, max_data_bytes-1);
+ nBytes = IMIN(1275, max_data_bytes-1-redundancy_bytes);
st->silk_mode.maxBits = nBytes*8;
/* Only allow up to 90% of the bits for hybrid mode*/
@@ -941,8 +951,6 @@
/* Reduce the initial target to make it easier to reach the CBR rate */
st->silk_mode.bitRate = IMAX(1, st->silk_mode.bitRate-2000);
}
- if (redundancy)
- st->silk_mode.maxBits -= st->silk_mode.maxBits/(1 + frame_size/(st->Fs/200));
if (prefill)
{@@ -990,6 +998,7 @@
}
st->silk_mode.opusCanSwitch = st->silk_mode.switchReady;
+ /* FIXME: How do we allocate the redundancy for CBR? */
if (st->silk_mode.opusCanSwitch)
{redundancy = 1;
@@ -1047,7 +1056,7 @@
celt_encoder_ctl(celt_enc, OPUS_SET_VBR(1));
celt_encoder_ctl(celt_enc, OPUS_SET_VBR_CONSTRAINT(st->vbr_constraint));
celt_encoder_ctl(celt_enc, OPUS_SET_BITRATE(st->bitrate_bps));
- nb_compr_bytes = max_data_bytes-1;
+ nb_compr_bytes = max_data_bytes-1-redundancy_bytes;
} else {nb_compr_bytes = bytes_target;
}
@@ -1119,8 +1128,10 @@
}
if (!redundancy)
+ {st->silk_bw_switch = 0;
-
+ redundancy_bytes = 0;
+ }
if (st->mode != MODE_CELT_ONLY)start_band=17;
if (st->mode == MODE_SILK_ONLY)