diff --git a/src/audio/audio_converter.cpp b/src/audio/audio_converter.cpp index 77773c5b..dc2fef95 100644 --- a/src/audio/audio_converter.cpp +++ b/src/audio/audio_converter.cpp @@ -25,7 +25,7 @@ [[maybe_unused]] static constexpr char kTag[] = "mixer"; static constexpr std::size_t kSampleBufferLength = - drivers::kI2SBufferLengthFrames * sizeof(sample::Sample) * 2; + drivers::kI2SBufferLengthFrames * sizeof(sample::Sample); static constexpr std::size_t kSourceBufferLength = kSampleBufferLength * 2; namespace audio { diff --git a/src/audio/audio_decoder.cpp b/src/audio/audio_decoder.cpp index 5b057240..bd728e5a 100644 --- a/src/audio/audio_decoder.cpp +++ b/src/audio/audio_decoder.cpp @@ -48,7 +48,7 @@ namespace audio { [[maybe_unused]] static const char* kTag = "audio_dec"; static constexpr std::size_t kCodecBufferLength = - drivers::kI2SBufferLengthFrames * sizeof(sample::Sample) * 2; + drivers::kI2SBufferLengthFrames * sizeof(sample::Sample); Timer::Timer(std::shared_ptr t, const codecs::ICodec::OutputFormat& format) diff --git a/src/drivers/include/i2s_dac.hpp b/src/drivers/include/i2s_dac.hpp index fdd7e976..bd837ca0 100644 --- a/src/drivers/include/i2s_dac.hpp +++ b/src/drivers/include/i2s_dac.hpp @@ -27,10 +27,12 @@ namespace drivers { -// We normalise to 2-channel, 16 bit audio, which gives us a max of 4092 / 2 / 2 -// (16 bits) frames. This in turn means that at 48kHz, we have about 10ms of -// budget to fill each buffer. -constexpr size_t kI2SBufferLengthFrames = 512; +// DMA max buffer size for I2S is 4092. We normalise to 2-channel, 16 bit +// audio, which gives us a max of 4092 / 2 / 2 (16 bits) frames. This in turn +// means that at 48kHz, we have about 21ms of budget to fill each buffer. +// We base this off of the maximum DMA size in order to minimise the amount of +// work the CPU has to do to service the DMA callbacks. +constexpr size_t kI2SBufferLengthFrames = 1024; /** * Interface for a DAC that receives PCM samples over I2S.