diff options
| -rw-r--r-- | libavcodec/acelp_filters.c | 13 | ||||
| -rw-r--r-- | libavcodec/acelp_filters.h | 2 |
2 files changed, 7 insertions, 8 deletions
diff --git a/libavcodec/acelp_filters.c b/libavcodec/acelp_filters.c index b98c6f7..7e33a67 100644 --- a/libavcodec/acelp_filters.c +++ b/libavcodec/acelp_filters.c @@ -37,13 +37,12 @@ void ff_acelp_convolve_circ( memset(fc_out, 0, subframe_size * sizeof(int16_t)); - /* Since there are few pulses over entire subframe (i.e. almost all - fc_in[i] are zero, in case of G.729D the buffer contains two non-zero - samples before the call to ff_acelp_enhance_harmonics, and (due to - pitch_delay bounded to [20; 143]) a maximum four non-zero samples - for a total of 40 after the call to it), it is faster to swap two loops - and process non-zero samples only. This will reduce the number of - multiplications from 40*40 to 4*40 for G.729D */ + /* Since there are few pulses over an entire subframe (i.e. almost + all fc_in[i] are zero) it is faster to swap two loops and process + non-zero samples only. In the case of G.729D the buffer contains + two non-zero samples before the call to ff_acelp_enhance_harmonics + and, due to pitch_delay being bounded by [20; 143], a maximum + of four non-zero samples for a total of 40 after the call. */ for(i=0; i<subframe_size; i++) { if(fc_in[i]) diff --git a/libavcodec/acelp_filters.h b/libavcodec/acelp_filters.h index 155a847..37f3a73 100644 --- a/libavcodec/acelp_filters.h +++ b/libavcodec/acelp_filters.h @@ -97,7 +97,7 @@ void ff_acelp_weighted_filter( * \note Two items before the top of the out buffer must contain two items from the * tail of the previous subframe. * - * \remark It is safe to pass the same array in in and out parameters + * \remark It is safe to pass the same array in in and out parameters. * * \remark AMR uses mostly the same filter (cut-off frequency 60Hz, same formula, * but constants differs in 5th sign after comma). Fortunately in |
