From e2a09db92b5e9de9375100fe639d032b1edced54 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@octasic.com>
Date: Wed, 2 Mar 2011 17:54:43 -0500
Subject: [PATCH] Implementing decoder-side support for redundant mode
switching (bemasc's idea)
---
src/opus_decoder.c | 22 +++++++++++++++++-----
src/opus_decoder.h | 1 +
src/opus_encoder.c | 13 +++++++++++++
3 files changed, 31 insertions(+), 5 deletions(-)
diff --git a/src/opus_decoder.c b/src/opus_decoder.c
index 41671ebef..1ebc3ea2e 100644
--- a/src/opus_decoder.c
+++ b/src/opus_decoder.c
@@ -83,6 +83,8 @@ int opus_decode(OpusDecoder *st, const unsigned char *data,
int audiosize;
int mode;
int transition=0;
+ int start_band;
+ int redundancy;
/* Payloads of 1 (2 including ToC) or 0 trigger the PLC/DTX */
if (len<=2)
@@ -130,7 +132,8 @@ int opus_decode(OpusDecoder *st, const unsigned char *data,
&& !(mode == MODE_HYBRID && st->prev_mode == MODE_SILK_ONLY))
{
transition = 1;
- opus_decode(st, NULL, 0, pcm_transition, IMAX(480, audiosize), 0);
+ if (mode == MODE_CELT_ONLY && !st->prev_redundancy)
+ opus_decode(st, NULL, 0, pcm_transition, IMAX(480, audiosize), 0);
}
if (audiosize > frame_size)
{
@@ -185,13 +188,21 @@ int opus_decode(OpusDecoder *st, const unsigned char *data,
pcm[i] = 0;
}
+ start_band = 0;
if (mode == MODE_HYBRID)
{
- /* This should be adjusted based on the SILK bandwidth */
- celt_decoder_ctl(st->celt_dec, CELT_SET_START_BAND(17));
- } else {
- celt_decoder_ctl(st->celt_dec, CELT_SET_START_BAND(0));
+ /* Check if we have a redundant 0-8 kHz band */
+ redundancy = ec_dec_bit_logp(&dec, 12);
+ if (!redundancy)
+ start_band = 17;
}
+ celt_decoder_ctl(st->celt_dec, CELT_SET_START_BAND(start_band));
+
+ if (redundancy)
+ transition = 0;
+
+ if (transition && mode != MODE_CELT_ONLY)
+ opus_decode(st, NULL, 0, pcm_transition, IMAX(480, audiosize), 0);
if (mode != MODE_SILK_ONLY)
{
@@ -242,6 +253,7 @@ int opus_decode(OpusDecoder *st, const unsigned char *data,
#endif
st->prev_mode = mode;
+ st->prev_redundancy = redundancy;
return celt_ret<0 ? celt_ret : audiosize;
}
diff --git a/src/opus_decoder.h b/src/opus_decoder.h
index 1b0569c22..037c87b72 100644
--- a/src/opus_decoder.h
+++ b/src/opus_decoder.h
@@ -41,6 +41,7 @@ struct OpusDecoder {
/* Sampling rate (at the API level) */
int Fs;
int prev_mode;
+ int prev_redundancy;
#ifdef OPUS_TEST_RANGE_CODER_STATE
int rangeFinal;
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index 2334aa2bd..2c2e589fc 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -95,6 +95,8 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
int silk_internal_bandwidth;
int bytes_target;
int prefill=0;
+ int start_band;
+ int redundancy = 0;
bytes_target = st->bitrate_bps * frame_size / (st->Fs * 8) - 1;
@@ -213,6 +215,17 @@ int opus_encode(OpusEncoder *st, const short *pcm, int frame_size,
} else {
celt_encoder_ctl(st->celt_enc, CELT_SET_PREDICTION(2));
}
+
+ start_band = 0;
+ if (st->mode == MODE_HYBRID)
+ {
+ /* Check if we have a redundant 0-8 kHz band */
+ ec_enc_bit_logp(&enc, redundancy, 12);
+ if (!redundancy)
+ start_band = 17;
+ }
+ celt_encoder_ctl(st->celt_enc, CELT_SET_START_BAND(start_band));
+
if (st->mode == MODE_HYBRID)
{
int len;
--
GitLab