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encoder/flac: refactor input buffer conversion

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This commit is contained in:
Max Kellermann 2022-07-12 12:24:59 +02:00
parent 00b8ced09f
commit 0158a2b6b9
1 changed files with 32 additions and 48 deletions
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80
src/encoder/plugins/FlacEncoderPlugin.cxx
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@ -24,11 +24,14 @@
#include "util/DynamicFifoBuffer.hxx"
#include "util/RuntimeError.hxx"
#include "util/Serial.hxx"
#include "util/SpanCast.hxx"
#include "util/StringUtil.hxx"
#include <FLAC/stream_encoder.h>
#include <FLAC/metadata.h>
#include <algorithm>
#if !defined(FLAC_API_VERSION_CURRENT) || FLAC_API_VERSION_CURRENT <= 7
#error libFLAC is too old
#endif
@ -249,67 +252,48 @@ FlacEncoder::SendTag(const Tag &tag)
FLAC__StreamEncoderInitStatusString[init_status]);
}
static inline void
pcm8_to_flac(int32_t *out, const int8_t *in, std::size_t num_samples) noexcept
template<typename T>
static std::span<const FLAC__int32>
ToFlac32(PcmBuffer &buffer, std::span<const T> src) noexcept
{
while (num_samples > 0) {
*out++ = *in++;
--num_samples;
}
FLAC__int32 *dest = buffer.GetT<FLAC__int32>(src.size());
std::copy(src.begin(), src.end(), dest);
return {dest, src.size()};
}
static inline void
pcm16_to_flac(int32_t *out, const int16_t *in, std::size_t num_samples) noexcept
static std::span<const FLAC__int32>
ToFlac32(PcmBuffer &buffer, std::span<const std::byte> src,
SampleFormat format)
{
while (num_samples > 0) {
*out++ = *in++;
--num_samples;
switch (format) {
case SampleFormat::S8:
return ToFlac32(buffer, FromBytesStrict<const int8_t>(src));
case SampleFormat::S16:
return ToFlac32(buffer, FromBytesStrict<const int16_t>(src));
case SampleFormat::S24_P32:
case SampleFormat::S32:
/* nothing need to be done; format is the same for
both mpd and libFLAC */
return FromBytesStrict<const int32_t>(src);
default:
gcc_unreachable();
}
}
void
FlacEncoder::Write(std::span<const std::byte> src)
{
void *exbuffer;
const void *buffer = nullptr;
/* format conversion */
const std::size_t num_frames = src.size() / audio_format.GetFrameSize();
const std::size_t num_samples = num_frames * audio_format.channels;
switch (audio_format.format) {
case SampleFormat::S8:
exbuffer = expand_buffer.Get(src.size() * 4);
pcm8_to_flac((int32_t *)exbuffer, (const int8_t *)src.data(),
num_samples);
buffer = exbuffer;
break;
case SampleFormat::S16:
exbuffer = expand_buffer.Get(src.size() * 2);
pcm16_to_flac((int32_t *)exbuffer, (const int16_t *)src.data(),
num_samples);
buffer = exbuffer;
break;
case SampleFormat::S24_P32:
case SampleFormat::S32:
/* nothing need to be done; format is the same for
both mpd and libFLAC */
buffer = src.data();
break;
default:
gcc_unreachable();
}
const auto imported = ToFlac32(expand_buffer, src,
audio_format.format);
const std::size_t n_frames = imported.size() / audio_format.channels;
/* feed samples to encoder */
if (!FLAC__stream_encoder_process_interleaved(fse,
(const FLAC__int32 *)buffer,
num_frames))
if (!FLAC__stream_encoder_process_interleaved(fse, imported.data(),
n_frames))
throw std::runtime_error("flac encoder process failed");
}