multi-stream fix when setting bitrate to AUTO, MAX, or small values
OPUS_AUTO should now work fine, while using OPUS_BITRATE_MAX would still
be a bad idea for controlling CBR rate for multistream. The encoder should
now throw an error early on if max_data_bytes is just too small to do anything.
diff --git a/src/opus_multistream_encoder.c b/src/opus_multistream_encoder.c
index 6e52a4d..aa464f5 100644
--- a/src/opus_multistream_encoder.c
+++ b/src/opus_multistream_encoder.c
@@ -591,7 +591,7 @@
return st;
}
-static void surround_rate_allocation(
+static opus_int32 surround_rate_allocation(
OpusMSEncoder *st,
opus_int32 *rate,
int frame_size
@@ -605,6 +605,7 @@
int lfe_offset;
int coupled_ratio; /* Q8 */
int lfe_ratio; /* Q8 */
+ opus_int32 rate_sum=0;
ptr = (char*)st + align(sizeof(OpusMSEncoder));
opus_encoder_ctl((OpusEncoder*)ptr, OPUS_GET_SAMPLE_RATE(&Fs));
@@ -660,7 +661,10 @@
rate[i] = stream_offset+channel_rate;
else
rate[i] = lfe_offset+(channel_rate*lfe_ratio>>8);
+ rate[i] = IMAX(rate[i], 500);
+ rate_sum += rate[i];
}
+ return rate_sum;
}
/* Max size in case the encoder decides to return three frames */
@@ -695,6 +699,8 @@
opus_val32 *mem = NULL;
opus_val32 *preemph_mem=NULL;
int frame_size;
+ opus_int32 rate_sum;
+ opus_int32 smallest_packet;
ALLOC_STACK;
if (st->surround)
@@ -738,6 +744,18 @@
RESTORE_STACK;
return OPUS_BAD_ARG;
}
+ /* Estimate (slightly overestimating) of the smallest packet the encoder can produce. */
+ if (50*frame_size <= Fs)
+ {
+ smallest_packet = st->layout.nb_streams*4;
+ } else {
+ smallest_packet = st->layout.nb_streams*4*50*frame_size/Fs;
+ }
+ if (max_data_bytes < smallest_packet)
+ {
+ RESTORE_STACK;
+ return OPUS_BAD_ARG;
+ }
ALLOC(buf, 2*frame_size, opus_val16);
coupled_size = opus_encoder_get_size(2);
mono_size = opus_encoder_get_size(1);
@@ -755,11 +773,19 @@
}
/* Compute bitrate allocation between streams (this could be a lot better) */
- surround_rate_allocation(st, bitrates, frame_size);
+ rate_sum = surround_rate_allocation(st, bitrates, frame_size);
if (!vbr)
- max_data_bytes = IMIN(max_data_bytes, 3*st->bitrate_bps/(3*8*Fs/frame_size));
-
+ {
+ if (st->bitrate_bps == OPUS_AUTO)
+ {
+ max_data_bytes = IMIN(max_data_bytes, 3*rate_sum/(3*8*Fs/frame_size));
+ } else if (st->bitrate_bps != OPUS_BITRATE_MAX)
+ {
+ max_data_bytes = IMIN(max_data_bytes, IMAX(smallest_packet,
+ 3*st->bitrate_bps/(3*8*Fs/frame_size)));
+ }
+ }
ptr = (char*)st + align(sizeof(OpusMSEncoder));
for (s=0;s<st->layout.nb_streams;s++)
{