From 278389defeeb9ea26100ca8f4783f44c9b446fa5 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Fri, 17 May 2013 02:03:33 -0400
Subject: [PATCH] Automatic bandwidth decisions get more conservative as rate
increases.
This should prevent errors in the bandwidth detection from affecting quality
when we have enough bits to be close to transparent.
---
celt/celt.h | 1 -
src/analysis.c | 12 ------------
src/analysis.h | 1 -
src/opus_encoder.c | 36 ++++++++++++++++++++++++++++++------
4 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/celt/celt.h b/celt/celt.h
index 0404d9181..c4b3ddbab 100644
--- a/celt/celt.h
+++ b/celt/celt.h
@@ -58,7 +58,6 @@ typedef struct {
opus_val16 activity;
opus_val16 music_prob;
int bandwidth;
- int opus_bandwidth;
}AnalysisInfo;
#define __celt_check_mode_ptr_ptr(ptr) ((ptr) + ((ptr) - (const CELTMode**)(ptr)))
diff --git a/src/analysis.c b/src/analysis.c
index b978b6e05..ee71bda65 100644
--- a/src/analysis.c
+++ b/src/analysis.c
@@ -575,19 +575,7 @@ void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info_out, con
printf("%f ", features[i]);
printf("\n");*/
- if (bandwidth<=12)
- tonal->opus_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
- else if (bandwidth<=14)
- tonal->opus_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
- else if (bandwidth<=16)
- tonal->opus_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
- else if (bandwidth<=18)
- tonal->opus_bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND;
- else
- tonal->opus_bandwidth = OPUS_BANDWIDTH_FULLBAND;
-
info->bandwidth = bandwidth;
- info->opus_bandwidth = tonal->opus_bandwidth;
/*printf("%d %d\n", info->bandwidth, info->opus_bandwidth);*/
info->noisiness = frame_noisiness;
info->valid = 1;
diff --git a/src/analysis.h b/src/analysis.h
index 7b17118cf..bce94a510 100644
--- a/src/analysis.h
+++ b/src/analysis.h
@@ -60,7 +60,6 @@ typedef struct {
int last_music;
int last_transition;
int count;
- int opus_bandwidth;
opus_val32 subframe_mem[3];
int analysis_offset;
float pspeech[DETECT_SIZE];
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index 29ac96796..1f2491aec 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -941,9 +941,21 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
st->detected_bandwidth = 0;
if (analysis_info->valid)
{
+ int analysis_bandwidth;
if (st->signal_type == OPUS_AUTO)
st->voice_ratio = (int)floor(.5+100*(1-analysis_info->music_prob));
- st->detected_bandwidth = analysis_info->opus_bandwidth;
+
+ analysis_bandwidth = analysis_info->bandwidth;
+ if (analysis_bandwidth<=12)
+ st->detected_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
+ else if (analysis_bandwidth<=14)
+ st->detected_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
+ else if (analysis_bandwidth<=16)
+ st->detected_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
+ else if (analysis_bandwidth<=18)
+ st->detected_bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND;
+ else
+ st->detected_bandwidth = OPUS_BANDWIDTH_FULLBAND;
}
#endif
@@ -1217,12 +1229,24 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_
/* Use detected bandwidth to reduce the encoded bandwidth. */
if (st->detected_bandwidth && st->user_bandwidth == OPUS_AUTO)
{
- /* When operating in SILK/hybrid mode, we don't go below wideband to avoid
- more complicated switches that require redundancy */
- if (st->mode == MODE_CELT_ONLY)
- st->bandwidth = IMIN(st->bandwidth, st->detected_bandwidth);
+ int min_detected_bandwidth;
+ /* Makes bandwidth detection more conservative just in case the detector
+ gets it wrong when we could have coded a high bandwidth transparently.
+ When operating in SILK/hybrid mode, we don't go below wideband to avoid
+ more complicated switches that require redundancy. */
+ if (st->bitrate_bps <= 18000*st->stream_channels && st->mode == MODE_CELT_ONLY)
+ min_detected_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
+ else if (st->bitrate_bps <= 24000*st->stream_channels && st->mode == MODE_CELT_ONLY)
+ min_detected_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
+ else if (st->bitrate_bps <= 30000*st->stream_channels)
+ min_detected_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
+ else if (st->bitrate_bps <= 44000*st->stream_channels)
+ min_detected_bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND;
else
- st->bandwidth = IMIN(st->bandwidth, IMAX(OPUS_BANDWIDTH_WIDEBAND, st->detected_bandwidth));
+ min_detected_bandwidth = OPUS_BANDWIDTH_FULLBAND;
+
+ st->detected_bandwidth = IMAX(st->detected_bandwidth, min_detected_bandwidth);
+ st->bandwidth = IMIN(st->bandwidth, st->detected_bandwidth);
}
#endif
celt_encoder_ctl(celt_enc, OPUS_SET_LSB_DEPTH(lsb_depth));
--
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