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Commit a2340c31 authored by Max Kellermann's avatar Max Kellermann
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pcm/PcmDop: round down to the nearest multiple of 4 DSD bytes

There was a discrepancy between what was written to the buffer and the size returned by pcm_dsd_to_dop(): the "for" loop uses num_frames/2, rounding down, while the return value is num_samples which is num_frames*channels, without rounding. This could cause undefined data at the end of the destination buffer if the source buffer size was not aligned to multiples of 8 bytes (4 DSD bytes per channel). The latter however can occur in the 0.21 branch after commit a06bf388 Closes #233
parent 37b07a5e
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src/pcm/PcmDop.cxx
View file @ a2340c31
...@@ -49,16 +49,17 @@ pcm_dsd_to_dop(PcmBuffer &buffer, unsigned channels, ...@@ -49,16 +49,17 @@ pcm_dsd_to_dop(PcmBuffer &buffer, unsigned channels,
const size_t num_src_samples = _src.size; const size_t num_src_samples = _src.size;
const size_t num_src_frames = num_src_samples / channels; const size_t num_src_frames = num_src_samples / channels;
/* this rounds down and discards the last odd frame; not /* this rounds down and discards up to 3 odd frames; not
elegant, but good enough for now */ elegant, but good enough for now */
const size_t num_frames = num_src_frames / 2; const size_t num_dop_quads = num_src_frames / 4;
const size_t num_frames = num_dop_quads * 2;
const size_t num_samples = num_frames * channels; const size_t num_samples = num_frames * channels;
uint32_t *const dest0 = (uint32_t *)buffer.GetT<uint32_t>(num_samples), uint32_t *const dest0 = (uint32_t *)buffer.GetT<uint32_t>(num_samples),
*dest = dest0; *dest = dest0;
auto src = _src.data; auto src = _src.data;
for (size_t i = num_frames / 2; i > 0; --i) { for (size_t i = num_dop_quads; i > 0; --i) {
for (unsigned c = channels; c > 0; --c) { for (unsigned c = channels; c > 0; --c) {
/* each 24 bit sample has 16 DSD sample bits /* each 24 bit sample has 16 DSD sample bits
plus the magic 0x05 marker */ plus the magic 0x05 marker */
......
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