diff options
Diffstat (limited to 'src/codecs/mad.cpp')
| -rw-r--r-- | src/codecs/mad.cpp | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/src/codecs/mad.cpp b/src/codecs/mad.cpp index 7e5b350b..dd839537 100644 --- a/src/codecs/mad.cpp +++ b/src/codecs/mad.cpp @@ -1,4 +1,5 @@ #include "mad.hpp" +#include <stdint.h> #include <cstdint> @@ -9,9 +10,9 @@ namespace codecs { -static int scaleTo16Bits(mad_fixed_t sample) { +static uint32_t scaleToBits(mad_fixed_t sample, uint8_t bits) { // Round the bottom bits. - sample += (1L << (MAD_F_FRACBITS - 16)); + sample += (1L << (MAD_F_FRACBITS - bits)); // Clip the leftover bits to within range. if (sample >= MAD_F_ONE) @@ -20,7 +21,7 @@ static int scaleTo16Bits(mad_fixed_t sample) { sample = -MAD_F_ONE; // Quantize. - return sample >> (MAD_F_FRACBITS + 1 - 16); + return sample >> (MAD_F_FRACBITS + 1 - bits); } MadMp3Decoder::MadMp3Decoder() { @@ -119,8 +120,19 @@ auto MadMp3Decoder::WriteOutputSamples(cpp::span<std::byte> output) } for (int channel = 0; channel < synth_.pcm.channels; channel++) { + // TODO(jacqueline): output 24 bit samples when (if?) we have a downmix + // step in the pipeline. + /* + uint32_t sample_24 = + scaleToBits(synth_.pcm.samples[channel][current_sample_], 24); + output[output_byte++] = static_cast<std::byte>((sample_24 >> 16) & 0xFF); + output[output_byte++] = static_cast<std::byte>((sample_24 >> 8) & 0xFF); + output[output_byte++] = static_cast<std::byte>((sample_24)&0xFF); + // 24 bit samples must still be aligned to 32 bits. The LSB is ignored. + output[output_byte++] = static_cast<std::byte>(0); + */ uint16_t sample_16 = - scaleTo16Bits(synth_.pcm.samples[channel][current_sample_]); + scaleToBits(synth_.pcm.samples[channel][current_sample_], 16); output[output_byte++] = static_cast<std::byte>((sample_16 >> 8) & 0xFF); output[output_byte++] = static_cast<std::byte>((sample_16)&0xFF); } |