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Simplify code to read index/predictor 

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@27146 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
reimar 2008-06-29 08:20:42 +00:00
parent 2f1ffb093b
commit 8666dab4f0
1 changed files with 28 additions and 57 deletions
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85
libmpcodecs/ad_imaadpcm.c
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@ -184,42 +184,25 @@ static void decode_nibbles(unsigned short *output,
static int qt_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int initial_predictor_l = 0;
int initial_predictor_r = 0;
int initial_index_l = 0;
int initial_index_r = 0;
int initial_predictor[2];
int initial_index[2];
int i;
if (channels > 1) channels = 2;
if (block_size < channels * QT_IMA_ADPCM_BLOCK_SIZE)
return -1;
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;
for (i = 0; i < channels; i++) {
initial_index[i] = initial_predictor[i] = BE_16(&input[i * QT_IMA_ADPCM_BLOCK_SIZE]);
// mask, sign-extend, and clamp the predictor portion
initial_predictor_r &= 0xFF80;
SE_16BIT(initial_predictor_r);
CLAMP_S16(initial_predictor_r);
initial_predictor[i] &= 0xFF80;
SE_16BIT(initial_predictor[i]);
CLAMP_S16(initial_predictor[i]);
// mask and clamp the index portion
initial_index_r &= 0x7F;
CLAMP_0_TO_88(initial_index_r);
initial_index[i] &= 0x7F;
CLAMP_0_TO_88(initial_index[i]);
}
// break apart all of the nibbles in the block
@ -240,8 +223,8 @@ static int qt_ima_adpcm_decode_block(unsigned short *output,
decode_nibbles(output,
QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels, channels,
initial_predictor_l, initial_index_l,
initial_predictor_r, initial_index_r);
initial_predictor[0], initial_index[0],
initial_predictor[1], initial_index[1]);
return QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels;
}
@ -249,10 +232,8 @@ static int qt_ima_adpcm_decode_block(unsigned short *output,
static int ms_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int predictor_l = 0;
int predictor_r = 0;
int index_l = 0;
int index_r = 0;
int predictor[2];
int index[2];
int i;
int channel_counter;
int channel_index;
@ -263,14 +244,10 @@ static int ms_ima_adpcm_decode_block(unsigned short *output,
if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
return -1;
predictor_l = LE_16(&input[0]);
SE_16BIT(predictor_l);
index_l = input[2];
if (channels == 2)
{
predictor_r = LE_16(&input[4]);
SE_16BIT(predictor_r);
index_r = input[6];
for (i = 0; i < channels; i++) {
predictor[i] = LE_16(&input[i * 4]);
SE_16BIT(predictor[i]);
index[i] = input[i * 4 + 2];
}
if (channels == 1)
@ -314,8 +291,8 @@ static int ms_ima_adpcm_decode_block(unsigned short *output,
decode_nibbles(output,
(block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2,
channels,
predictor_l, index_l,
predictor_r, index_r);
predictor[0], index[0],
predictor[1], index[1]);
return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2;
}
@ -325,24 +302,18 @@ static int dk4_ima_adpcm_decode_block(unsigned short *output,
{
int i;
int output_ptr;
int predictor_l = 0;
int predictor_r = 0;
int index_l = 0;
int index_r = 0;
int predictor[2];
int index[2];
if (channels > 1) channels = 2;
if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
return -1;
// the first predictor value goes straight to the output
predictor_l = output[0] = LE_16(&input[0]);
SE_16BIT(predictor_l);
index_l = input[2];
if (channels == 2)
{
predictor_r = output[1] = LE_16(&input[4]);
SE_16BIT(predictor_r);
index_r = input[6];
for (i = 0; i < channels; i++) {
// the first predictor value goes straight to the output
predictor[i] = output[i] = LE_16(&input[i * 4]);
SE_16BIT(predictor[i]);
index[i] = input[i * 4 + 2];
}
output_ptr = channels;
@ -355,8 +326,8 @@ static int dk4_ima_adpcm_decode_block(unsigned short *output,
decode_nibbles(&output[channels],
(block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels,
channels,
predictor_l, index_l,
predictor_r, index_r);
predictor[0], index[0],
predictor[1], index[1]);
return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels;
}