//Duplicate every other sample to make it seem like its half speed
int HalfPlay(data_file file_, int l_, int* clusters_)
{
int i, j, r = 0;
BYTE playBuffer[BUF_SIZE] = {0};
for (i = 0; i < l_ * BPB_SecPerClus; i++)
{
if (_playing == 0)
break;
//Buffer current sector (i) from cluster into the playBuffer
get_rel_sector(&file_, playBuffer, clusters_, i);
for (j = 0; j < BUF_SIZE; j+=2)
{
//Wait for signal to write for audio, then write to it with prepared bytes
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
//Logic to play the bytes twice (repeat every 4 bits)
if (j % 4 == 0)
{
if (r == 1){
r = 0;
}else{
j -= 4;
r = 1;
}
}
}
}
}
int DelayPlay(data_file file_, int l_, int* clusters_)
{
int i, j;
//Create an additional delay buffer with the size of sample rate
BYTE playBuffer[BUF_SIZE] = {0};
UINT16 delayBuffer[SAMPLE_RATE] = {0};
int idxDelay, flag = 0;
//Iterate through the audio
for (i = 0; i < l_ * BPB_SecPerClus; i++)
{
if (_playing == 0)
break;
get_rel_sector(&file_, playBuffer, clusters_, i);
for (j = 0; j < BUF_SIZE; j+=2)
{
//Wait for signal to write for audio, then write to it with prepared bytes
while(IORD(AUD_FULL_BASE, 0)){}
//Populate delayBuffer using idxDelay with what's in playBuffer on an edge
if (flag == 0){
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
flag = 1;
}else{
IOWR(AUDIO_0_BASE, 0, delayBuffer[idxDelay]);
delayBuffer[idxDelay] = BytePrep(playBuffer[j], playBuffer[j + 1]);
flag = 0;
}
//If we exceed the buffer size, loop around to beginning of array
idxDelay++;
if (idxDelay > SAMPLE_RATE)
idxDelay = idxDelay % SAMPLE_RATE;
}
}
//Finish from current delay index to end of delay array
for (i = idxDelay; i < SAMPLE_RATE; i++)
{
if (_playing == 0)
break;
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0, delayBuffer[i]);
}
//Finish last remaining audio data from beginning to delayIdx
for (i = 0; i < idxDelay; i++)
{
if (_playing == 0)
break;
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0, delayBuffer[i]);
}
}
//Plays the audio backwards by iterating from end of buffer to the beginning
int ReversePlay(data_file file_, int l_, int* clusters_)
{
int i, j;
BYTE playBuffer[BUF_SIZE] = {0};
for (i = l_ * BPB_SecPerClus; i > 0; i--)
{
if (_playing == 0)
break;
get_rel_sector(&file_, playBuffer, clusters_, i);
//Starts from the end and works backwards
for (j = 508; j > 0; j-=6)
{
//Wait for signal to write for audio, then write to it with prepared bytes
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
//To play the next 2 bits of reverse batch (right side)
j+=2;
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
}
}
}
void play_normal(data_file* file, BYTE buffer[], int cluster_chain[]){
int isector = 0, ibyte, retval, num_bytes;
UINT16 tmp;
while (player_state == PLAYER_STATE_PLAYING){
retval = get_rel_sector(file, buffer, cluster_chain, isector++);
if (retval != -1){
num_bytes = (retval == 0) ? BPB_BytsPerSec : retval;
for (ibyte = 0; (player_state == PLAYER_STATE_PLAYING) && (ibyte < num_bytes); ibyte += 2){
tmp = (buffer[ibyte + 1] << 8) | (buffer[ibyte]);
while(IORD(AUD_FULL_BASE, 0));
IOWR(AUDIO_0_BASE, 0, tmp);
}
}
}
}
void play_reverse(data_file* file, BYTE buffer[], int cluster_chain[]){
int isector = ceil(file->FileSize/BPB_BytsPerSec) - 1, ibyte, retval, num_bytes;
UINT16 tmp;
while (player_state == PLAYER_STATE_PLAYING){
retval = get_rel_sector(file, buffer, cluster_chain, isector--);
if (retval != -1){
num_bytes = (retval == 0) ? BPB_BytsPerSec : retval;
for (ibyte = num_bytes - 1; ibyte >= 1; ibyte -= 2){
tmp = (buffer[ibyte] << 8) | (buffer[ibyte-1]);
while(IORD(AUD_FULL_BASE, 0));
IOWR(AUDIO_0_BASE, 0, tmp);
}
}
}
}
//Play song in regular speed
int NormalPlay(data_file file_, int l_, int* clusters_)
{
int i, j;
BYTE playBuffer[BUF_SIZE] = {0};
for (i = 0; i < l_ * BPB_SecPerClus; i++)
{
//If play flag is defaulted (user stops music), then stop playing from buffer
if (_playing == 0)
break;
//Buffer current sector (i) from cluster into the playBuffer
get_rel_sector(&file_, playBuffer, clusters_, i);
for (j = 0; j < BUF_SIZE; j+=2){
//Wait for signal to write for audio, then write to it with prepared bytes
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
}
}
}
void play_delay(data_file* file, BYTE buffer[], int cluster_chain[]){
UINT16 tmp, data;
int isector = 0, ibyte, ilagbuf = 0, channel = CHANNEL_LEFT, retval, num_bytes;
UINT16 lag_buffer[DELAY_SAMPLES] = {0x0000};
while (player_state == PLAYER_STATE_PLAYING){
retval = get_rel_sector(file, buffer, cluster_chain, isector++);
if (retval != -1) {
num_bytes = (retval == 0) ? BPB_BytsPerSec : retval;
for (ibyte = 0; (player_state == PLAYER_STATE_PLAYING) && (ibyte < num_bytes); ibyte += 2){
data = (buffer[ibyte + 1] << 8) | (buffer[ibyte]);
if (channel == CHANNEL_LEFT){
tmp = data;
} else {
if (ilagbuf == DELAY_SAMPLES) ilagbuf = 0;
tmp = lag_buffer[ilagbuf];
lag_buffer[ilagbuf++] = data;
}
while(IORD(AUD_FULL_BASE, 0));
IOWR(AUDIO_0_BASE, 0, tmp);
channel ^= 1;
}
}
}
int i;
for (i = 0; i < DELAY_SAMPLES*2 && player_state == PLAYER_STATE_PLAYING; i++){
if (ilagbuf == DELAY_SAMPLES) ilagbuf = 0;
tmp = (channel == CHANNEL_LEFT) ? 0x0000 : lag_buffer[ilagbuf++];
while(IORD(AUD_FULL_BASE, 0));
IOWR(AUDIO_0_BASE, 0, tmp);
channel ^=1 ;
}
}
//Skips every other sample to make it seem like its playing double speed.
int DoublePlay(data_file file_, int l_, int* clusters_)
{
int i, j = 0;
BYTE playBuffer[BUF_SIZE] = {0};
for (i = 0; i < l_ * BPB_SecPerClus; i++)
{
if (_playing == 0)
break;
//Buffer current sector (i) from cluster into the playBuffer
get_rel_sector(&file_, playBuffer, clusters_, i);
for (j = 0; j < BUF_SIZE; j+=2)
{
//Wait for signal to write for audio, then write to it with prepared bytes
while(IORD(AUD_FULL_BASE, 0)){}
IOWR(AUDIO_0_BASE, 0 , BytePrep(playBuffer[j], playBuffer[j + 1]));
//Skip 2 lefts and 2 rights every 2 lefts and 2 rights... get it? HAHAHAHAA
if (j % 4 == 0)
j += 4;
}
}
}
void play_music(int playType){
/* Play Types
* 0 = Normal
* 1 = Double
* 2 = Half
* 3 = Delay
* 4 = Reverse
*/
int sectorSize;
secCount = playType == 4 ? (floor( (float) returnData.FileSize/512) - 1) : 0;
sectorSize = get_rel_sector(&returnData, buffer, cc, secCount);
while(sectorSize != -1){
if(stop_flag)
break;
if(sectorSize == 0){
if(playType == 0 || playType == 4)
write_to_codec(buffer,BPB_BytsPerSec);
else if(playType == 1)
write_to_codec_double(buffer,BPB_BytsPerSec);
else if(playType == 2)
write_to_codec_half(buffer,BPB_BytsPerSec);
else{
UINT16 tmp;
int i;
for (i = 0; (i+4) < BPB_BytsPerSec; i+=4){
rightBuffer[delay_cnt] = buffer[i+2];
rightBuffer[delay_cnt+1] = buffer[i+3];
delay_cnt += 2;
if ((delay_cnt + 1) >= 88200){
delay_cnt = 0;
}
tmp = ((buffer[i+1] << 8) | (buffer[i]));
while(IORD(AUD_FULL_BASE,0)) {} // Wait until FIFO is ready
IOWR(AUDIO_0_BASE, 0 , tmp);
tmp = ((rightBuffer[delay_cnt+1] << 8) | (rightBuffer[delay_cnt]));
while(IORD(AUD_FULL_BASE,0)) {} // Wait until FIFO is ready
IOWR(AUDIO_0_BASE, 0 , tmp);
}
}
}
else{
if(playType == 0 || playType == 4)
write_to_codec(buffer,sectorSize);
else if(playType == 1)
write_to_codec_double(buffer,sectorSize);
else if(playType == 2)
write_to_codec_half(buffer,sectorSize);
else{
printf("Playing End of Delay");
write_to_codec_delay(buffer,sectorSize);
}
}
secCount = playType == 4 ? secCount - 1 : secCount + 1 ;
sectorSize = get_rel_sector(&returnData, buffer, cc, secCount);
}
// Reset stop_flag
if (stop_flag == 1)
stop_flag = 0;
else
stop_flag = 1;
}
