mic_u: Fix up logic for populating shared memory sample buffer. (#6669)

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Steveice10 2023-07-07 19:02:31 -07:00 committed by GitHub
parent e5310b25d4
commit cd3244f139
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@ -80,23 +80,29 @@ struct State {
void WriteSamples(std::span<const u8> samples) {
u32 bytes_total_written = 0;
const std::size_t remaining_space = size - offset;
std::size_t bytes_to_write = std::min(samples.size(), remaining_space);
auto sample_buffer = sharedmem_buffer + initial_offset;
// Do not let sampling buffer overrun shared memory space.
const auto sample_buffer_size =
std::min(size, sharedmem_size - initial_offset - sizeof(u32));
// Write as many samples as we can to the buffer.
// TODO if the sample size is 16bit, this could theoretically cut a sample in the case where
// the application configures an odd size
std::memcpy(sharedmem_buffer + offset, samples.data(), bytes_to_write);
offset += static_cast<u32>(bytes_to_write);
bytes_total_written += static_cast<u32>(bytes_to_write);
// If theres any samples left to write after we looped, go ahead and write them now
if (looped_buffer && samples.size() > bytes_total_written) {
offset = initial_offset;
bytes_to_write = std::min(samples.size() - bytes_total_written, size);
std::memcpy(sharedmem_buffer + offset, samples.data() + bytes_total_written,
// Write samples in a loop until the input runs out
while (samples.size() > bytes_total_written) {
// TODO: If the sample size is 16-bit, this could theoretically cut a sample in the case
// where the application configures an odd size.
std::size_t bytes_to_write =
std::min(samples.size() - bytes_total_written, sample_buffer_size - offset);
std::memcpy(sample_buffer + offset, samples.data() + bytes_total_written,
bytes_to_write);
offset += static_cast<u32>(bytes_to_write);
bytes_total_written += static_cast<u32>(bytes_to_write);
if (offset >= sample_buffer_size && looped_buffer) {
offset = 0;
}
if (!looped_buffer) {
break;
}
}
// The last 4 bytes of the shared memory contains the latest offset
@ -205,7 +211,8 @@ struct MIC_U::Impl {
}
u8 sample_size = encoding == Encoding::PCM8Signed || encoding == Encoding::PCM8 ? 8 : 16;
state.offset = state.initial_offset = audio_buffer_offset;
state.offset = 0;
state.initial_offset = audio_buffer_offset;
state.sample_rate = sample_rate;
state.sample_size = sample_size;
state.looped_buffer = audio_buffer_loop;