diff options
Diffstat (limited to 'src/lib/formats/flacfile.cpp')
| -rw-r--r-- | src/lib/formats/flacfile.cpp | 78 |
1 files changed, 74 insertions, 4 deletions
diff --git a/src/lib/formats/flacfile.cpp b/src/lib/formats/flacfile.cpp index f3ccb676e52..c594a809a8e 100644 --- a/src/lib/formats/flacfile.cpp +++ b/src/lib/formats/flacfile.cpp @@ -16,10 +16,27 @@ #include <new> -static constexpr int MAX_CHANNELS = 8; +namespace { +constexpr int MAX_CHANNELS = 8; -static cassette_image::error flacfile_identify(cassette_image *cassette, cassette_image::Options *opts) + +// Copied from cassimg.cpp; put somewhere central? +/********************************************************************* + helper code +*********************************************************************/ +constexpr double map_double(double d, uint64_t low, uint64_t high, uint64_t value) +{ + return d * (value - low) / (high - low); +} + +constexpr size_t waveform_bytes_per_sample(int waveform_flags) +{ + return size_t(1 << ((waveform_flags & 0x06) / 2)); +} + + +cassette_image::error flacfile_identify(cassette_image *cassette, cassette_image::Options *opts) { cassette->get_raw_cassette_image()->seek(0, SEEK_SET); flac_decoder decoder(*cassette->get_raw_cassette_image()); @@ -42,7 +59,7 @@ static cassette_image::error flacfile_identify(cassette_image *cassette, cassett } -static cassette_image::error flacfile_load(cassette_image *cassette) +cassette_image::error flacfile_load(cassette_image *cassette) { cassette->get_raw_cassette_image()->seek(0, SEEK_SET); flac_decoder decoder(*cassette->get_raw_cassette_image()); @@ -73,10 +90,63 @@ static cassette_image::error flacfile_load(cassette_image *cassette) } +cassette_image::error flacfile_save(cassette_image *cassette, const cassette_image::Info *info) +{ + if (info->channels > MAX_CHANNELS) + return cassette_image::error::INVALID_IMAGE; + + cassette->get_raw_cassette_image()->seek(0, SEEK_SET); + flac_encoder encoder; + encoder.set_num_channels(info->channels); + encoder.set_sample_rate(info->sample_frequency); + if (!encoder.reset(*cassette->get_raw_cassette_image())) + return cassette_image::error::INTERNAL; + + size_t samples_saved = 0; + int16_t buffer[MAX_CHANNELS][4096]; + int16_t *buffer_ptr[MAX_CHANNELS]; + const size_t bytes_per_sample = waveform_bytes_per_sample(cassette_image::WAVEFORM_16BIT); + const size_t sample_spacing = bytes_per_sample * info->channels; + const double sample_period = info->sample_count / (double) info->sample_frequency; + + for (int channel = 0; channel < MAX_CHANNELS; channel++) + { + buffer_ptr[channel] = &buffer[channel][0]; + } + + while (samples_saved < info->sample_count) + { + size_t chunk_sample_count = std::min(sizeof(buffer) / sample_spacing, (info->sample_count - samples_saved)); + double chunk_sample_period = map_double(sample_period, 0, info->sample_count, chunk_sample_count); + double chunk_time_index = map_double(sample_period, 0, info->sample_count, samples_saved); + + for (int channel = 0; channel < info->channels; channel++) + { + cassette_image::error err = cassette->get_samples(channel, chunk_time_index, chunk_sample_period, + chunk_sample_count, sample_spacing, &buffer[channel * bytes_per_sample], cassette_image::WAVEFORM_16BIT); + + if (err != cassette_image::error::SUCCESS) + return err; + } + + if (!encoder.encode(buffer_ptr, chunk_sample_count)) + return cassette_image::error::INTERNAL; + + samples_saved += chunk_sample_count; + } + + encoder.finish(); + + return cassette_image::error::SUCCESS; +} + +} // anonymous namespace + + const cassette_image::Format cassette_image::flacfile_format = { "flac", flacfile_identify, flacfile_load, - nullptr + flacfile_save }; |
