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AWavLoader: Share code between 24/16/8 bit reading

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The only part of this that actually differs between all of them is the
stream -> sample reading, so turn that into a function that the channel
reader can call as it wants.
This commit is contained in:
Robin Burchell 2019-07-18 13:32:54 +02:00 • committed by Andreas Kling
parent a2fbfb6cef
commit d19136ce07
1 changed files with 33 additions and 54 deletions
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87
Libraries/LibAudio/AWavLoader.cpp
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@ -155,11 +155,10 @@ bool AResampleHelper::read_sample()
return false;
}
template <typename T>
static void read_samples_from_stream(BufferStream& stream, Vector<ASample>& samples, int num_channels, int source_rate)
template <typename SampleReader>
static void read_samples_from_stream(BufferStream& stream, SampleReader read_sample, Vector<ASample>& samples, int num_channels, int source_rate)
{
AResampleHelper resampler(source_rate, 44100);
T sample = 0;
float norm_l = 0;
float norm_r = 0;
switch (num_channels) {
@ -167,8 +166,7 @@ static void read_samples_from_stream(BufferStream& stream, Vector<ASample>& samp
while (!stream.handle_read_failure()) {
resampler.prepare();
while (resampler.read_sample()) {
stream >> sample;
norm_l = float(sample) / std::numeric_limits<T>::max();
norm_l = read_sample(stream);
}
samples.append(ASample(norm_l));
}
@ -177,10 +175,8 @@ static void read_samples_from_stream(BufferStream& stream, Vector<ASample>& samp
while (!stream.handle_read_failure()) {
resampler.prepare();
while (resampler.read_sample()) {
stream >> sample;
norm_l = float(sample) / std::numeric_limits<T>::max();
stream >> sample;
norm_r = float(sample) / std::numeric_limits<T>::max();
norm_l = read_sample(stream);
norm_r = read_sample(stream);
}
samples.append(ASample(norm_l, norm_r));
}
@ -190,52 +186,35 @@ static void read_samples_from_stream(BufferStream& stream, Vector<ASample>& samp
}
}
static void read_24bit_samples_from_stream(BufferStream& stream, Vector<ASample>& samples, int num_channels, int source_rate)
static float read_norm_sample_24(BufferStream& stream)
{
AResampleHelper resampler(source_rate, 44100);
u8 byte = 0;
stream >> byte;
u32 sample1 = byte;
stream >> byte;
u32 sample2 = byte;
stream >> byte;
u32 sample3 = byte;
auto read_norm_sample = [&stream]() {
u8 byte = 0;
stream >> byte;
u32 sample1 = byte;
stream >> byte;
u32 sample2 = byte;
stream >> byte;
u32 sample3 = byte;
i32 value = 0;
value = sample1 << 8;
value |= (sample2 << 16);
value |= (sample3 << 24);
return float(value) / std::numeric_limits<i32>::max();
}
i32 value = 0;
value = sample1 << 8;
value |= (sample2 << 16);
value |= (sample3 << 24);
return float(value) / std::numeric_limits<i32>::max();
};
static float read_norm_sample_16(BufferStream& stream)
{
i16 sample = 0;
stream >> sample;
return float(sample) / std::numeric_limits<i16>::max();
}
float norm_l = 0;
float norm_r = 0;
switch (num_channels) {
case 1:
while (!stream.handle_read_failure()) {
resampler.prepare();
while (resampler.read_sample()) {
norm_l = read_norm_sample();
}
samples.append(ASample(norm_l));
}
break;
case 2:
while (!stream.handle_read_failure()) {
resampler.prepare();
while (resampler.read_sample()) {
norm_l = read_norm_sample();
norm_r = read_norm_sample();
}
samples.append(ASample(norm_l, norm_r));
}
break;
default:
ASSERT_NOT_REACHED();
}
static float read_norm_sample_8(BufferStream& stream)
{
u8 sample = 0;
stream >> sample;
return float(sample) / std::numeric_limits<u8>::max();
}
// ### can't const this because BufferStream is non-const
@ -251,13 +230,13 @@ RefPtr<ABuffer> ABuffer::from_pcm_data(ByteBuffer& data, int num_channels, int b
switch (bits_per_sample) {
case 8:
read_samples_from_stream<u8>(stream, fdata, num_channels, source_rate);
read_samples_from_stream(stream, read_norm_sample_8, fdata, num_channels, source_rate);
break;
case 16:
read_samples_from_stream<i16>(stream, fdata, num_channels, source_rate);
read_samples_from_stream(stream, read_norm_sample_16, fdata, num_channels, source_rate);
break;
case 24:
read_24bit_samples_from_stream(stream, fdata, num_channels, source_rate);
read_samples_from_stream(stream, read_norm_sample_24, fdata, num_channels, source_rate);
break;
default:
ASSERT_NOT_REACHED();