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pcm/PcmDsd: add converter from DSD_U8 to DSD_U32

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This commit is contained in:
Max Kellermann 2016-02-26 18:15:16 +01:00
parent c9761bf6af
commit d1be643c0d
2 changed files with 44 additions and 0 deletions
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38
src/pcm/PcmDsd.cxx
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@ -71,3 +71,41 @@ PcmDsd::ToFloat(unsigned channels, ConstBuffer<uint8_t> src)
return { dest, num_samples };
}
/**
* Construct a 32 bit integer from four bytes.
*/
static constexpr inline uint32_t
Construct32(uint8_t a, uint8_t b, uint8_t c, uint8_t d)
{
return uint32_t(a) | (uint32_t(b) << 8) |
(uint32_t(c) << 16) | (uint32_t(d) << 24);
}
static constexpr inline uint32_t
Dsd8To32Sample(const uint8_t *src, unsigned channels)
{
return Construct32(src[0], src[channels],
src[2 * channels], src[3 * channels]);
}
ConstBuffer<uint32_t>
Dsd8To32(PcmBuffer &buffer, unsigned channels, ConstBuffer<uint8_t> _src)
{
const size_t in_frames = _src.size / channels;
const size_t out_frames = in_frames / 4;
const size_t out_samples = out_frames * channels;
const uint8_t *src = _src.data;
uint32_t *const dest0 = buffer.GetT<uint32_t>(out_samples);
uint32_t *dest = dest0;
for (size_t i = 0; i < out_frames; ++i) {
for (size_t c = 0; c < channels; ++c)
*dest++ = Dsd8To32Sample(src++, channels);
src += 3 * channels;
}
return {dest0, out_samples};
}

6
src/pcm/PcmDsd.hxx
View File

@ -48,4 +48,10 @@ public:
ConstBuffer<uint8_t> src);
};
/**
* Convert DSD_U8 to DSD_U32 (native endian).
*/
ConstBuffer<uint32_t>
Dsd8To32(PcmBuffer &buffer, unsigned channels, ConstBuffer<uint8_t> src);
#endif