static int qt_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int initial_predictor[2] = {0};
int initial_index[2] = {0};
int i;
if (channels != 1) channels = 2;
if (block_size < channels * QT_IMA_ADPCM_BLOCK_SIZE)
return -1;
for (i = 0; i < channels; i++) {
initial_index[i] = initial_predictor[i] = (int16_t)AV_RB16(&input[i * QT_IMA_ADPCM_BLOCK_SIZE]);
// mask, sign-extend, and clamp the predictor portion
initial_predictor[i] &= ~0x7F;
CLAMP_S16(initial_predictor[i]);
// mask and clamp the index portion
initial_index[i] &= 0x7F;
CLAMP_0_TO_88(initial_index[i]);
}
// break apart all of the nibbles in the block
if (channels == 1)
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
{
output[i * 2 + 0] = input[2 + i] & 0x0F;
output[i * 2 + 1] = input[2 + i] >> 4;
}
else
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
int qt_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels)
{
int initial_predictor_l = 0;
int initial_predictor_r = 0;
int initial_index_l = 0;
int initial_index_r = 0;
int i;
initial_predictor_l = BE_16(&input[0]);
initial_index_l = initial_predictor_l;
// mask, sign-extend, and clamp the predictor portion
initial_predictor_l &= 0xFF80;
SE_16BIT(initial_predictor_l);
CLAMP_S16(initial_predictor_l);
// mask and clamp the index portion
initial_index_l &= 0x7F;
CLAMP_0_TO_88(initial_index_l);
// handle stereo
if (channels > 1)
{
initial_predictor_r = BE_16(&input[QT_IMA_ADPCM_BLOCK_SIZE]);
initial_index_r = initial_predictor_r;
// mask, sign-extend, and clamp the predictor portion
initial_predictor_r &= 0xFF80;
SE_16BIT(initial_predictor_r);
CLAMP_S16(initial_predictor_r);
// mask and clamp the index portion
initial_index_r &= 0x7F;
CLAMP_0_TO_88(initial_index_r);
}
// break apart all of the nibbles in the block
if (channels == 1)
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
{
output[i * 2 + 0] = input[2 + i] & 0x0F;
output[i * 2 + 1] = input[2 + i] >> 4;
}
else
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2 * 2; i++)
static void decode_nibbles(unsigned short *output,
int output_size, int channels,
int predictor_l, int index_l,
int predictor_r, int index_r)
{
int step[2];
int predictor[2];
int index[2];
int diff;
int i;
int sign;
int delta;
int channel_number = 0;
step[0] = adpcm_step[index_l];
step[1] = adpcm_step[index_r];
predictor[0] = predictor_l;
predictor[1] = predictor_r;
index[0] = index_l;
index[1] = index_r;
for (i = 0; i < output_size; i++)
{
delta = output[i];
index[channel_number] += adpcm_index[delta];
CLAMP_0_TO_88(index[channel_number]);
sign = delta & 8;
delta = delta & 7;
diff = step[channel_number] >> 3;
if (delta & 4) diff += step[channel_number];
if (delta & 2) diff += step[channel_number] >> 1;
if (delta & 1) diff += step[channel_number] >> 2;
if (sign)
predictor[channel_number] -= diff;
else
predictor[channel_number] += diff;
CLAMP_S16(predictor[channel_number]);
output[i] = predictor[channel_number];
step[channel_number] = adpcm_step[index[channel_number]];
// toggle channel
channel_number ^= channels - 1;
}
}
static void decode_nibbles(unsigned short *output,
int output_size, int channels,
int predictor[2], int index[2])
{
int step[2];
int i;
int sign;
int delta;
int channel_number = 0;
step[0] = adpcm_step[index[0]];
step[1] = adpcm_step[index[1]];
for (i = 0; i < output_size; i++)
{
delta = output[i];
sign = delta & 8;
delta = delta & 7;
index[channel_number] += adpcm_index[delta];
CLAMP_0_TO_88(index[channel_number]);
delta = 2 * delta + 1;
if (sign) delta = -delta;
predictor[channel_number] += (delta * step[channel_number]) >> 3;
CLAMP_S16(predictor[channel_number]);
output[i] = predictor[channel_number];
step[channel_number] = adpcm_step[index[channel_number]];
// toggle channel
channel_number ^= channels - 1;
}
}
// note: This decoder assumes the format 0x62 data always comes in
// stereo flavor
static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
int block_size)
{
int sum_pred;
int diff_pred;
int sum_index;
int diff_index;
int diff_channel;
int in_ptr = 0x10;
int out_ptr = 0;
unsigned char last_byte = 0;
unsigned char nibble;
int decode_top_nibble_next = 0;
// ADPCM work variables
int sign;
int delta;
int step;
int diff;
sum_pred = LE_16(&input[10]);
diff_pred = LE_16(&input[12]);
SE_16BIT(sum_pred);
SE_16BIT(diff_pred);
diff_channel = diff_pred;
sum_index = input[14];
diff_index = input[15];
while (in_ptr < block_size - !decode_top_nibble_next)
// while (in_ptr < 2048)
{
// process the first predictor of the sum channel
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[sum_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
sum_pred -= diff;
else
sum_pred += diff;
CLAMP_S16(sum_pred);
sum_index += adpcm_index[nibble];
CLAMP_0_TO_88(sum_index);
// process the diff channel predictor
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[diff_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
diff_pred -= diff;
else
diff_pred += diff;
CLAMP_S16(diff_pred);
diff_index += adpcm_index[nibble];
CLAMP_0_TO_88(diff_index);
// output the first pair of stereo PCM samples
diff_channel = (diff_channel + diff_pred) / 2;
output[out_ptr++] = sum_pred + diff_channel;
output[out_ptr++] = sum_pred - diff_channel;
// process the second predictor of the sum channel
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[sum_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
sum_pred -= diff;
else
sum_pred += diff;
CLAMP_S16(sum_pred);
sum_index += adpcm_index[nibble];
CLAMP_0_TO_88(sum_index);
// output the second pair of stereo PCM samples
output[out_ptr++] = sum_pred + diff_channel;
output[out_ptr++] = sum_pred - diff_channel;
}
return out_ptr;
}
