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Add support for 24-64 bit audio. Based on a patch by SAPikachu. Updates #1292.

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Originally committed to SVN as r5797.
This commit is contained in:
Thomas Goyne 2011-10-29 03:46:44 +00:00
parent 7f06849531
commit f9408031b6
1 changed files with 57 additions and 10 deletions
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67
aegisub/src/audio_provider_convert.cpp
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@ -87,6 +87,54 @@ public:
}
};
/// (16,64] bit signed -> 16 bit signed machine-endian audio converter
class DownconvertAudioProvider : public AudioProviderConverter {
std::vector<char> src_buf;
int src_bytes_per_sample;
bool src_is_native_endian;
public:
DownconvertAudioProvider(AudioProvider *src) : AudioProviderConverter(src) {
if (bytes_per_sample <= 2 || bytes_per_sample > 8)
throw agi::InternalError("DownconvertAudioProvider requires (16,64]-bit input", 0);
src_is_native_endian = src->AreSamplesNativeEndian();
src_bytes_per_sample = bytes_per_sample;
bytes_per_sample = 2;
}
void GetAudio(void *buf, int64_t start, int64_t count) const {
src_buf.resize(count * src_bytes_per_sample * channels);
source->GetAudio(&src_buf[0], start, count);
int16_t *dest = reinterpret_cast<int16_t*>(buf);
for (int64_t i = 0; i < count * channels; ++i) {
int64_t sample = 0;
char *sample_ptr = (char*)&sample;
char *src = &src_buf[i * src_bytes_per_sample];
if (src_is_native_endian) {
#ifdef HAVE_LITTLE_ENDIAN
memcpy(sample_ptr, src, src_bytes_per_sample);
#else
memcpy(sample_ptr + sizeof(int64_t) - src_bytes_per_sample, src, src_bytes_per_sample);
#endif
}
else {
for (int byte_index = 0; i < src_bytes_per_sample; ++i) {
#ifdef HAVE_LITTLE_ENDIAN
sample_ptr[byte_index] = src[src_bytes_per_sample - byte_index - 1];
#else
sample_ptr[sizeof(int64_t) - byte_index - 1] = src[byte_index];
#endif
}
}
sample >>= (src_bytes_per_sample - sizeof(int16_t)) * 8;
dest[i] = (int16_t)sample;
}
}
};
/// Non-mono 16-bit signed machine-endian -> mono 16-bit signed machine endian converter
class DownmixAudioProvider : public AudioProviderConverter {
mutable std::vector<int16_t> src_buf;
@ -162,17 +210,16 @@ AudioProvider *CreateConvertAudioProvider(AudioProvider *source_provider) {
AudioProvider *provider = source_provider;
// Ensure 16-bit audio with proper endianness
switch (provider->GetBytesPerSample()) {
case 1:
provider = new UpconvertAudioProvider(provider);
break;
case 2:
if (!provider->AreSamplesNativeEndian())
provider = new EndianSwapAudioProvider(provider);
break;
default:
throw AudioOpenError("Audio format converter: audio with bitdepths greater than 16 bits/sample is currently unsupported");
if (provider->GetBytesPerSample() == 1)
provider = new UpconvertAudioProvider(provider);
else if (provider->GetBytesPerSample() == 1) {
if (!provider->AreSamplesNativeEndian())
provider = new EndianSwapAudioProvider(provider);
}
else if (provider->GetBytesPerSample() <= 8)
provider = new DownconvertAudioProvider(provider);
else
throw AudioOpenError("Audio format converter: audio with bitdepths greater than 64 bits/sample is currently unsupported");
// We currently only support mono audio
if (provider->GetChannels() != 1)