mirror of
https://github.com/libretro/dolphin
synced 2024-11-09 06:53:01 -05:00
df631f0d75
Added class in AudioCommon for the surround decoder
94 lines
3 KiB
C++
94 lines
3 KiB
C++
// Copyright 2017 Dolphin Emulator Project
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// Licensed under GPLv2+
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// Refer to the license.txt file included.
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#include <FreeSurround/FreeSurroundDecoder.h>
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#include <limits>
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#include "AudioCommon/SurroundDecoder.h"
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namespace AudioCommon
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{
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constexpr size_t STEREO_CHANNELS = 2;
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constexpr size_t SURROUND_CHANNELS = 6;
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SurroundDecoder::SurroundDecoder(u32 sample_rate, u32 frame_block_size)
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: m_sample_rate(sample_rate), m_frame_block_size(frame_block_size)
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{
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m_fsdecoder = std::make_unique<DPL2FSDecoder>();
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m_fsdecoder->Init(cs_5point1, m_frame_block_size, m_sample_rate);
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}
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SurroundDecoder::~SurroundDecoder() = default;
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void SurroundDecoder::Clear()
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{
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m_fsdecoder->flush();
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m_decoded_fifo.clear();
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}
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// Currently only 6 channels are supported.
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size_t SurroundDecoder::QueryFramesNeededForSurroundOutput(const size_t output_frames) const
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{
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if (m_decoded_fifo.size() < output_frames * SURROUND_CHANNELS)
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{
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// Output stereo frames needed to have at least the desired number of surround frames
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size_t frames_needed = output_frames - m_decoded_fifo.size() / SURROUND_CHANNELS;
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return frames_needed + m_frame_block_size - frames_needed % m_frame_block_size;
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}
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return 0;
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}
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// Receive and decode samples
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void SurroundDecoder::PutFrames(const short* in, const size_t num_frames_in)
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{
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// Maybe check if it is really power-of-2?
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s64 remaining_frames = static_cast<s64>(num_frames_in);
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size_t frame_index = 0;
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while (remaining_frames > 0)
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{
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// Convert to float
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for (size_t i = 0, end = m_frame_block_size * STEREO_CHANNELS; i < end; ++i)
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{
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m_float_conversion_buffer[i] = in[i + frame_index * STEREO_CHANNELS] /
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static_cast<float>(std::numeric_limits<short>::max());
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}
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// Decode
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const float* dpl2_fs = m_fsdecoder->decode(m_float_conversion_buffer.data());
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// Add to ring buffer and fix channel mapping
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// Maybe modify FreeSurround to output the correct mapping?
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// FreeSurround:
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// FL | FC | FR | BL | BR | LFE
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// Most backends:
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// FL | FR | FC | LFE | BL | BR
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for (size_t i = 0; i < m_frame_block_size; ++i)
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{
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 0]); // LEFTFRONT
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 2]); // RIGHTFRONT
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 1]); // CENTREFRONT
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 5]); // sub/lfe
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 3]); // LEFTREAR
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m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 4]); // RIGHTREAR
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}
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remaining_frames = remaining_frames - static_cast<int>(m_frame_block_size);
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frame_index = frame_index + m_frame_block_size;
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}
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}
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void SurroundDecoder::ReceiveFrames(float* out, const size_t num_frames_out)
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{
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// Copy to output array with desired num_frames_out
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for (size_t i = 0, num_samples_output = num_frames_out * SURROUND_CHANNELS;
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i < num_samples_output; ++i)
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{
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out[i] = m_decoded_fifo.pop_front();
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}
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}
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} // namespace AudioCommon
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