From 7dca334da23565e3da08a6e9874ab132e60fcde7 Mon Sep 17 00:00:00 2001 From: Sascha Sommer Date: Sun, 6 Sep 2009 06:56:25 +0000 Subject: avoid extra memcpy during scale factor decoding Originally committed as revision 19777 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/wmaprodec.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'libavcodec/wmaprodec.c') diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c index 886ff45670..4d1d955498 100644 --- a/libavcodec/wmaprodec.c +++ b/libavcodec/wmaprodec.c @@ -137,8 +137,9 @@ typedef struct { int8_t reuse_sf; ///< share scale factors between subframes int8_t scale_factor_step; ///< scaling step for the current subframe int max_scale_factor; ///< maximum scale factor for the current subframe - int scale_factors[MAX_BANDS]; ///< scale factor values for the current subframe - int saved_scale_factors[MAX_BANDS]; ///< scale factors from a previous subframe + int saved_scale_factors[2][MAX_BANDS]; ///< resampled and (previously) transmitted scale factor values + int8_t scale_factor_idx; ///< index for the transmitted scale factor values (used for resampling) + int* scale_factors; ///< pointer to the scale factor values used for decoding uint8_t table_idx; ///< index in sf_offsets for the scale factor reference block float* coeffs; ///< pointer to the subframe decode buffer DECLARE_ALIGNED_16(float, out[WMAPRO_BLOCK_MAX_SIZE + WMAPRO_BLOCK_MAX_SIZE / 2]); ///< output buffer @@ -860,7 +861,9 @@ static int decode_scale_factors(WMAProDecodeCtx* s) for (i = 0; i < s->channels_for_cur_subframe; i++) { int c = s->channel_indexes_for_cur_subframe[i]; int* sf; - int* sf_end = s->channel[c].scale_factors + s->num_bands; + int* sf_end; + s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx]; + sf_end = s->channel[c].scale_factors + s->num_bands; /** resample scale factors for the new block size * as the scale factors might need to be resampled several times @@ -872,7 +875,7 @@ static int decode_scale_factors(WMAProDecodeCtx* s) int b; for (b = 0; b < s->num_bands; b++) s->channel[c].scale_factors[b] = - s->channel[c].saved_scale_factors[*sf_offsets++]; + s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++]; } if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) { @@ -919,12 +922,8 @@ static int decode_scale_factors(WMAProDecodeCtx* s) s->channel[c].scale_factors[i] += (val ^ sign) - sign; } } - - /** save transmitted scale factors so that they can be reused for - the next subframe */ - memcpy(s->channel[c].saved_scale_factors, - s->channel[c].scale_factors, s->num_bands * - sizeof(*s->channel[c].saved_scale_factors)); + /** swap buffers */ + s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx; s->channel[c].table_idx = s->table_idx; s->channel[c].reuse_sf = 1; } -- cgit v1.2.3