From 60f767713227b5405b855e6e6e2a0475ecd96bcc Mon Sep 17 00:00:00 2001 From: jacqueline Date: Fri, 4 Aug 2023 20:07:44 +1000 Subject: Do our own resampling --- src/codecs/include/codec.hpp | 6 ++-- src/codecs/include/foxenflac.hpp | 3 +- src/codecs/include/mad.hpp | 3 +- src/codecs/include/sample.hpp | 59 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+), 5 deletions(-) create mode 100644 src/codecs/include/sample.hpp (limited to 'src/codecs/include') diff --git a/src/codecs/include/codec.hpp b/src/codecs/include/codec.hpp index e8be8f0a..f260aca4 100644 --- a/src/codecs/include/codec.hpp +++ b/src/codecs/include/codec.hpp @@ -16,6 +16,7 @@ #include #include +#include "sample.hpp" #include "result.hpp" #include "span.hpp" #include "types.hpp" @@ -61,7 +62,6 @@ class ICodec { struct OutputFormat { uint8_t num_channels; - uint8_t bits_per_sample; uint32_t sample_rate_hz; std::optional duration_seconds; @@ -76,7 +76,7 @@ class ICodec { -> Result = 0; struct OutputInfo { - std::size_t bytes_written; + std::size_t samples_written; bool is_finished_writing; }; @@ -84,7 +84,7 @@ class ICodec { * Writes PCM samples to the given output buffer. */ virtual auto ContinueStream(cpp::span input, - cpp::span output) + cpp::span output) -> Result = 0; virtual auto SeekStream(cpp::span input, diff --git a/src/codecs/include/foxenflac.hpp b/src/codecs/include/foxenflac.hpp index cce1b762..abfa6d80 100644 --- a/src/codecs/include/foxenflac.hpp +++ b/src/codecs/include/foxenflac.hpp @@ -14,6 +14,7 @@ #include #include "foxen/flac.h" +#include "sample.hpp" #include "span.hpp" #include "codec.hpp" @@ -26,7 +27,7 @@ class FoxenFlacDecoder : public ICodec { ~FoxenFlacDecoder(); auto BeginStream(cpp::span) -> Result override; - auto ContinueStream(cpp::span, cpp::span) + auto ContinueStream(cpp::span, cpp::span) -> Result override; auto SeekStream(cpp::span input, std::size_t target_sample) -> Result override; diff --git a/src/codecs/include/mad.hpp b/src/codecs/include/mad.hpp index fbae560c..b81e4acb 100644 --- a/src/codecs/include/mad.hpp +++ b/src/codecs/include/mad.hpp @@ -13,6 +13,7 @@ #include #include "mad.h" +#include "sample.hpp" #include "span.hpp" #include "codec.hpp" @@ -35,7 +36,7 @@ class MadMp3Decoder : public ICodec { * Writes samples for the current frame. */ auto ContinueStream(cpp::span input, - cpp::span output) + cpp::span output) -> Result override; auto SeekStream(cpp::span input, std::size_t target_sample) diff --git a/src/codecs/include/sample.hpp b/src/codecs/include/sample.hpp new file mode 100644 index 00000000..7209673b --- /dev/null +++ b/src/codecs/include/sample.hpp @@ -0,0 +1,59 @@ +#pragma once + +#include + +#include + +#include + +namespace sample { + +// A signed, 32-bit PCM sample. +typedef int32_t Sample; + +constexpr auto Clip(int64_t v) -> Sample { + if (v > INT32_MAX) + return INT32_MAX; + if (v < INT32_MIN) + return INT32_MIN; + return v; +} + +constexpr auto FromSigned(int32_t src, uint_fast8_t bits) -> Sample { + // Left-align samples, effectively scaling them up to 32 bits. + return src << (sizeof(Sample) * 8 - bits); +} + +constexpr auto FromUnsigned(uint32_t src, uint_fast8_t bits) -> Sample { + // Left-align, then substract the max value / 2 to make the sample centred + // around zero. + return (src << (sizeof(uint32_t) * 8 - bits)) - (~0UL >> 1); +} + +constexpr auto FromFloat(float src) -> Sample { + return std::clamp(src, -1.0f, 1.0f) * static_cast(INT32_MAX); +} + +constexpr auto FromDouble(double src) -> Sample { + return std::clamp(src, -1.0, 1.0) * static_cast(INT32_MAX); +} + +constexpr auto FromMad(mad_fixed_t src) -> Sample { + // Round the bottom bits. + src += (1L << (MAD_F_FRACBITS - 24)); + + // Clip the leftover bits to within range. + if (src >= MAD_F_ONE) + src = MAD_F_ONE - 1; + else if (src < -MAD_F_ONE) + src = -MAD_F_ONE; + + // Quantize. + return FromSigned(src >> (MAD_F_FRACBITS + 1 - 24), 24); +} + +constexpr auto ToSigned16Bit(Sample src) -> uint16_t { + return src >> 16; +} + +} // namespace sample -- cgit v1.2.3 From a66c3428063017f2233b6b15d5ce6c920d5c9095 Mon Sep 17 00:00:00 2001 From: jacqueline Date: Mon, 7 Aug 2023 14:26:04 +1000 Subject: Resampling *basically* working? Just cleanup and buffering issues --- src/codecs/include/sample.hpp | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'src/codecs/include') diff --git a/src/codecs/include/sample.hpp b/src/codecs/include/sample.hpp index 7209673b..f8e08cdc 100644 --- a/src/codecs/include/sample.hpp +++ b/src/codecs/include/sample.hpp @@ -52,8 +52,14 @@ constexpr auto FromMad(mad_fixed_t src) -> Sample { return FromSigned(src >> (MAD_F_FRACBITS + 1 - 24), 24); } -constexpr auto ToSigned16Bit(Sample src) -> uint16_t { +constexpr auto ToSigned16Bit(Sample src) -> int16_t { return src >> 16; } +static constexpr float kFactor = 1.0f / static_cast(INT32_MAX); + +constexpr auto ToFloat(Sample src) -> float { + return src * kFactor; +} + } // namespace sample -- cgit v1.2.3 From c38754401b95642b5e61fd273c2adf7d76a829fe Mon Sep 17 00:00:00 2001 From: jacqueline Date: Mon, 7 Aug 2023 18:22:15 +1000 Subject: Downscaling working! --- src/codecs/include/codec.hpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/codecs/include') diff --git a/src/codecs/include/codec.hpp b/src/codecs/include/codec.hpp index f260aca4..32ebef69 100644 --- a/src/codecs/include/codec.hpp +++ b/src/codecs/include/codec.hpp @@ -16,8 +16,8 @@ #include #include -#include "sample.hpp" #include "result.hpp" +#include "sample.hpp" #include "span.hpp" #include "types.hpp" -- cgit v1.2.3