Files
mice-3ds/source/opus.c
Mahyar Koshkouei cdf49f8dcf play: add current and total time of music
Signed-off-by: Mahyar Koshkouei <mk@deltabeard.com>
2023-07-08 16:51:14 +01:00

154 lines
2.8 KiB
C

#include <stdlib.h>
#include <string.h>
#include "opus.h"
#include "playback.h"
static OggOpusFile* opusFile;
static const OpusHead* opusHead;
static const size_t buffSize = 32 * 1024;
static int initOpus(const char* file);
static uint32_t rateOpus(void);
static uint8_t channelOpus(void);
static uint64_t decodeOpus(void* buffer);
static void exitOpus(void);
static uint64_t fillOpusBuffer(int16_t* bufferOut);
static size_t getFileSamplesOpus(void);
/**
* Set decoder parameters for Opus.
*
* \param decoder Structure to store parameters.
*/
void setOpus(struct decoder_fn* decoder)
{
decoder->init = &initOpus;
decoder->rate = &rateOpus;
decoder->channels = &channelOpus;
decoder->buffSize = buffSize;
decoder->decode = &decodeOpus;
decoder->exit = &exitOpus;
decoder->getFileSamples = &getFileSamplesOpus;
}
static size_t getFileSamplesOpus(void)
{
ogg_int64_t len = op_pcm_total(opusFile, -1);
if(len == OP_EINVAL)
return 0;
return len * (size_t)channelOpus();
}
/**
* Initialise Opus decoder.
*
* \param file Location of opus file to play.
* \return 0 on success, else failure.
*/
int initOpus(const char* file)
{
int err = 0;
if((opusFile = op_open_file(file, &err)) == NULL)
goto out;
if((err = op_current_link(opusFile)) < 0)
goto out;
opusHead = op_head(opusFile, err);
out:
return err;
}
/**
* Get sampling rate of Opus file.
*
* \return Sampling rate. Should be 48000.
*/
uint32_t rateOpus(void)
{
return 48000;
}
/**
* Get number of channels of Opus file.
*
* \return Number of channels for opened file, so always be 2.
*/
uint8_t channelOpus(void)
{
/* Opus decoder always returns stereo stream */
return 2;
}
/**
* Decode part of open Opus file.
*
* \param buffer Decoded output.
* \return Samples read for each channel. 0 for end of file, negative
* for error.
*/
uint64_t decodeOpus(void* buffer)
{
return fillOpusBuffer(buffer);
}
/**
* Free Opus decoder.
*/
void exitOpus(void)
{
op_free(opusFile);
}
/**
* Decode Opus file to fill buffer.
*
* \param bufferOut Pointer to buffer.
* \return Samples read per channel.
*/
uint64_t fillOpusBuffer(int16_t* bufferOut)
{
uint64_t samplesRead = 0;
int samplesToRead = buffSize;
while(samplesToRead > 0)
{
int samplesJustRead = op_read_stereo(opusFile, bufferOut,
samplesToRead > 120*48*2 ? 120*48*2 : samplesToRead);
if(samplesJustRead < 0)
return samplesJustRead;
else if(samplesJustRead == 0)
{
/* End of file reached. */
break;
}
samplesRead += samplesJustRead * 2;
samplesToRead -= samplesJustRead * 2;
bufferOut += samplesJustRead * 2;
}
return samplesRead;
}
/**
* Checks if the input file is Opus.
*
* \param in Input file.
* \return 0 if Opus file, else not or failure.
*/
int isOpus(const char* in)
{
int err = 0;
OggOpusFile* opusTest = op_test_file(in, &err);
op_free(opusTest);
return err;
}