aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/alac.c
diff options
context:
space:
mode:
authorJustin Ruggles <justin.ruggles@gmail.com>2012-07-09 11:18:21 -0400
committerJustin Ruggles <justin.ruggles@gmail.com>2012-07-19 13:26:47 -0400
commitabc4376b31b672f8f38c30851cbe1acd016b6e18 (patch)
tree9b4dc36ec0bba2e307c7ad7dbc767a7ba6e1ed32 /libavcodec/alac.c
parent01880d287be6e2269b92eee8d9dc442532d277ea (diff)
downloadffmpeg-abc4376b31b672f8f38c30851cbe1acd016b6e18.tar.gz
alac: reduce the number of local variables needed in lpc prediction
Diffstat (limited to 'libavcodec/alac.c')
-rw-r--r--libavcodec/alac.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index b19973db50..7306e57405 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -204,28 +204,27 @@ static void predictor_decompress_fir_adapt(int32_t *error_buffer,
/* general case */
for (i = predictor_coef_num + 1; i < output_size; i++) {
int j;
- int sum = 0;
- int outval;
+ int val = 0;
int error_val = error_buffer[i];
for (j = 0; j < predictor_coef_num; j++) {
- sum += (buffer_out[predictor_coef_num-j] - buffer_out[0]) *
+ val += (buffer_out[predictor_coef_num-j] - buffer_out[0]) *
predictor_coef_table[j];
}
- outval = (1 << (predictor_quantitization-1)) + sum;
- outval = outval >> predictor_quantitization;
- outval = outval + buffer_out[0] + error_val;
- outval = sign_extend(outval, readsamplesize);
+ val = (val + (1 << (predictor_quantitization - 1))) >>
+ predictor_quantitization;
+ val += buffer_out[0] + error_val;
- buffer_out[predictor_coef_num+1] = outval;
+ buffer_out[predictor_coef_num + 1] = sign_extend(val, readsamplesize);
if (error_val > 0) {
int predictor_num = predictor_coef_num - 1;
while (predictor_num >= 0 && error_val > 0) {
- int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
- int sign = sign_only(val);
+ int sign;
+ val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
+ sign = sign_only(val);
predictor_coef_table[predictor_num] -= sign;
@@ -240,8 +239,9 @@ static void predictor_decompress_fir_adapt(int32_t *error_buffer,
int predictor_num = predictor_coef_num - 1;
while (predictor_num >= 0 && error_val < 0) {
- int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
- int sign = - sign_only(val);
+ int sign;
+ val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
+ sign = -sign_only(val);
predictor_coef_table[predictor_num] -= sign;