clownacy / clownresampler Goto Github PK

unsigned int channels_in;//number of channels in the wav file.
unsigned int sample_rate_in;//sample rate of the wav file.
drwav_uint64 total_frames_in;//length of the input wav file in PCM frames.
ClownResampler_Precomputed precomputed;
ClownResampler_LowLevel_State state;
size_t input_frame_count;
size_t output_frame_count;
drwav wav;//for writing the output to a wav file.
drwav_data_format out_format;//describes the format of the output wav file.
short* source;//contains the input data.
size_t out_buffer_size;//size of the output buffer that will be given to ClownResampler.

source = drwav_open_file_and_read_pcm_frames_s16("Lullaby improved.wav", &channels_in, &sample_rate_in, &total_frames_in, NULL);
assert(source != NULL);
out_buffer_size = ((double)total_frames_in / (double)sample_rate_in) * (double)OUT_RATE;//in PCM frames.
short* dest = (short*)malloc(out_buffer_size * sizeof (short) * channels_in);
assert(dest != NULL);

ClownResampler_Precompute(&precomputed);
ClownResampler_LowLevel_Init(&state, channels_in, sample_rate_in, OUT_RATE);
input_frame_count = total_frames_in - 128;//I know this is lazy: but instead of padding the beginning and end, I'm just allowing the first and last few samples to be sacrificed for the sake of a simple demo.
output_frame_count = total_frames_in;

ClownResampler_LowLevel_Resample(&state, &precomputed, source, &input_frame_count, dest, &output_frame_count);
output_frame_count = (out_buffer_size - output_frame_count);//convert number of frames not used to number of frames used.
input_frame_count = (total_frames_in - input_frame_count);

															 //Set the parameters and output a wav file containing the result.

out_format.bitsPerSample = 16;
out_format.channels = 2;
out_format.container = drwav_container_riff;
out_format.format = DR_WAVE_FORMAT_PCM;
out_format.sampleRate = 44100;

drwav_init_file_write(&wav, "clownresampler_distortion.wav", &out_format, NULL);
drwav_write_pcm_frames(&wav, output_frame_count, dest);
drwav_uninit(&wav);
drwav_free(source, NULL);
free(dest);

printf("%d PCM frames in and %d PCM frames out.", total_frames_in, output_frame_count);
getchar();