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author | Justin Ruggles <justin.ruggles@gmail.com> | 2012-07-09 11:18:21 -0400 |
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committer | Justin Ruggles <justin.ruggles@gmail.com> | 2012-07-19 13:26:47 -0400 |
commit | abc4376b31b672f8f38c30851cbe1acd016b6e18 (patch) | |
tree | 9b4dc36ec0bba2e307c7ad7dbc767a7ba6e1ed32 /libavcodec/alac.c | |
parent | 01880d287be6e2269b92eee8d9dc442532d277ea (diff) | |
download | ffmpeg-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.c | 24 |
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; |