Opus 1.4 Corrupted audio while encode of 128 channels #397
Description
Environment
Opus 1.4 (commit: 82ac57d)
OS: Win/MacOS
Repro steps
I have very simple encoder as below,
I try to encode 128 channels where I have sine wave on every channel,
I set total bitrate as 64kbps * 128 = 8192kbps
So I instantiate Encoder as follows:
Encoder encoder(8192, 48000, 128);
Actual result:
Audio corrupted on last channels, up to total loss of audio in last channel.
Issue can be reproduced on any number of channels depending on set total bitrate.
Expected result:
Audio should be of good quality in every channel if set total bitrate as 64kbps * channels
Results on different bitrates:
total bitrate 8192kbps - no audio on 128th channel at all:
total bitrate 16384kbps - it's 128kbps per channel, still 128th channel is corrupted:
Workaround:
Only after setting total bitrate to 20480kbps audio looks fine.
Encoder::Encoder(int bitrateKbps, int sampleRate, int numChannels)
{
int error = 0;
msEncoder_ = opus_multistream_encoder_create(sampleRate, numChannels, numChannels, 0, kChannelMapping.data(), OPUS_APPLICATION_AUDIO, &error);
if (error != OPUS_OK)
throw std::logic_error(std::string("Failed to create opus mulistream encoder, error: ") + opus_strerror(error));
opus_multistream_encoder_ctl(msEncoder_, OPUS_SET_BITRATE(bitrateKbps * 1000));
opus_multistream_encoder_ctl(msEncoder_, OPUS_SET_VBR(0));
opus_multistream_encoder_ctl(msEncoder_, OPUS_SET_PACKET_LOSS_PERC(5));
opus_multistream_encoder_ctl(msEncoder_, OPUS_SET_COMPLEXITY(5));
opus_multistream_encoder_ctl(msEncoder_, OPUS_SET_BANDWIDTH(OPUS_AUTO));
}
Encoder::~Encoder()
{
opus_multistream_encoder_destroy(msEncoder_);
}
bool Encoder::encode(const float* inBuf, int numInputSamples, unsigned char *outBuf, int outBufCapacity, int& encBytes)
{
encBytes = opus_multistream_encode_float(msEncoder_, inBuf, numInputSamples, outBuf, outBufCapacity);
if (encBytes < 0)
{
return false;
}
return true;
}