mirror of
https://github.com/badaix/snapcast.git
synced 2025-04-28 17:57:05 +02:00
122 lines
4.2 KiB
C++
122 lines
4.2 KiB
C++
/***
|
|
This file is part of snapcast
|
|
Copyright (C) 2015 Hannes Ellinger
|
|
Copyright (C) 2016-2024 Johannes Pohl
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
***/
|
|
|
|
// prototype/interface header file
|
|
#include "opus_decoder.hpp"
|
|
|
|
// local headers
|
|
#include "common/aixlog.hpp"
|
|
#include "common/snap_exception.hpp"
|
|
|
|
|
|
namespace decoder
|
|
{
|
|
|
|
#define ID_OPUS 0x4F505553
|
|
|
|
/// int: Number of samples per channel in the input signal.
|
|
/// This must be an Opus frame size for the encoder's sampling rate. For example, at 48 kHz the
|
|
/// permitted values are 120, 240, 480, 960, 1920, and 2880.
|
|
/// Passing in a duration of less than 10 ms (480 samples at 48 kHz) will prevent the encoder from using the LPC or hybrid modes.
|
|
static constexpr int const_max_frame_size = 2880;
|
|
|
|
static constexpr auto LOG_TAG = "OpusDecoder";
|
|
|
|
OpusDecoder::OpusDecoder() : Decoder(), dec_(nullptr)
|
|
{
|
|
pcm_.resize(120);
|
|
}
|
|
|
|
|
|
OpusDecoder::~OpusDecoder()
|
|
{
|
|
if (dec_ != nullptr)
|
|
opus_decoder_destroy(dec_);
|
|
}
|
|
|
|
|
|
bool OpusDecoder::decode(msg::PcmChunk* chunk)
|
|
{
|
|
int decoded_frames = 0;
|
|
|
|
while ((decoded_frames = opus_decode(dec_, reinterpret_cast<unsigned char*>(chunk->payload), chunk->payloadSize, pcm_.data(),
|
|
static_cast<int>(pcm_.size()) / sample_format_.channels(), 0)) == OPUS_BUFFER_TOO_SMALL)
|
|
{
|
|
if (pcm_.size() < const_max_frame_size * sample_format_.channels())
|
|
{
|
|
pcm_.resize(pcm_.size() * 2);
|
|
LOG(DEBUG, LOG_TAG) << "OPUS encoding buffer too small, resizing to " << pcm_.size() / sample_format_.channels() << " samples per channel\n";
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
|
|
if (decoded_frames < 0)
|
|
{
|
|
LOG(ERROR, LOG_TAG) << "Failed to decode chunk: " << opus_strerror(decoded_frames) << ", IN size: " << chunk->payloadSize
|
|
<< ", OUT size: " << pcm_.size() << '\n';
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
LOG(TRACE, LOG_TAG) << "Decode chunk: " << decoded_frames << " frames, size: " << chunk->payloadSize
|
|
<< " bytes, decoded: " << decoded_frames * sample_format_.frameSize() << " bytes\n";
|
|
|
|
// copy encoded data to chunk
|
|
chunk->payloadSize = decoded_frames * sample_format_.frameSize(); // decoded_frames * sample_format_.channels() * sizeof(opus_int16);
|
|
chunk->payload = static_cast<char*>(realloc(chunk->payload, chunk->payloadSize));
|
|
memcpy(chunk->payload, reinterpret_cast<char*>(pcm_.data()), chunk->payloadSize);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
|
|
SampleFormat OpusDecoder::setHeader(msg::CodecHeader* chunk)
|
|
{
|
|
// decode the opus pseudo header
|
|
if (chunk->payloadSize < 12)
|
|
throw SnapException("OPUS header too small");
|
|
|
|
// decode the "opus id" magic number, this is our constant part that must match
|
|
uint32_t id_opus;
|
|
memcpy(&id_opus, chunk->payload, sizeof(id_opus));
|
|
if (SWAP_32(id_opus) != ID_OPUS)
|
|
throw SnapException("Not an Opus pseudo header");
|
|
|
|
// decode the sampleformat
|
|
uint32_t rate;
|
|
memcpy(&rate, chunk->payload + 4, sizeof(rate));
|
|
uint16_t bits;
|
|
memcpy(&bits, chunk->payload + 8, sizeof(bits));
|
|
uint16_t channels;
|
|
memcpy(&channels, chunk->payload + 10, sizeof(channels));
|
|
|
|
sample_format_.setFormat(SWAP_32(rate), SWAP_16(bits), SWAP_16(channels));
|
|
LOG(DEBUG, LOG_TAG) << "Opus sampleformat: " << sample_format_.toString() << "\n";
|
|
|
|
// create the decoder
|
|
int error;
|
|
dec_ = opus_decoder_create(sample_format_.rate(), sample_format_.channels(), &error);
|
|
if (error != 0)
|
|
throw SnapException("Failed to initialize Opus decoder: " + std::string(opus_strerror(error)));
|
|
|
|
return sample_format_;
|
|
}
|
|
|
|
} // namespace decoder
|