[Ffmpeg-cvslog] r8526 - in trunk/libavcodec: wma.c wma.h wmadec.c wmaenc.c
banan
subversion
Mon Mar 26 12:03:57 CEST 2007
Author: banan
Date: Mon Mar 26 12:03:57 2007
New Revision: 8526
Modified:
trunk/libavcodec/wma.c
trunk/libavcodec/wma.h
trunk/libavcodec/wmadec.c
trunk/libavcodec/wmaenc.c
Log:
Optimize by building the mdct window and multipying/adding at the same time.
Patch by Ian Braithwaite ian .. braithwaite . dk
[Ffmpeg-devel] WMA decoder speedup 2007-03-22 22:56
Modified: trunk/libavcodec/wma.c
==============================================================================
--- trunk/libavcodec/wma.c (original)
+++ trunk/libavcodec/wma.c Mon Mar 26 12:03:57 2007
@@ -302,7 +302,7 @@ int ff_wma_init(AVCodecContext * avctx,
window = av_malloc(sizeof(float) * n);
alpha = M_PI / (2.0 * n);
for(j=0;j<n;j++) {
- window[n - j - 1] = sin((j + 0.5) * alpha);
+ window[j] = sin((j + 0.5) * alpha);
}
s->windows[i] = window;
}
Modified: trunk/libavcodec/wma.h
==============================================================================
--- trunk/libavcodec/wma.h (original)
+++ trunk/libavcodec/wma.h Mon Mar 26 12:03:57 2007
@@ -112,7 +112,6 @@ typedef struct WMACodecContext {
int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);
DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);
- DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]);
MDCTContext mdct_ctx[BLOCK_NB_SIZES];
float *windows[BLOCK_NB_SIZES];
DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); ///< temporary storage for imdct
Modified: trunk/libavcodec/wmadec.c
==============================================================================
--- trunk/libavcodec/wmadec.c (original)
+++ trunk/libavcodec/wmadec.c Mon Mar 26 12:03:57 2007
@@ -316,6 +316,61 @@ static int decode_exp_vlc(WMACodecContex
return 0;
}
+
+/**
+ * Apply MDCT window and add into output.
+ *
+ * We ensure that when the windows overlap their squared sum
+ * is always 1 (MDCT reconstruction rule).
+ */
+static void wma_window(WMACodecContext *s, float *out)
+{
+ float *in = s->output;
+ int block_len, bsize, n;
+
+ /* left part */
+ if (s->block_len_bits <= s->prev_block_len_bits) {
+ block_len = s->block_len;
+ bsize = s->frame_len_bits - s->block_len_bits;
+
+ s->dsp.vector_fmul_add_add(out, in, s->windows[bsize],
+ out, 0, block_len, 1);
+
+ } else {
+ block_len = 1 << s->prev_block_len_bits;
+ n = (s->block_len - block_len) / 2;
+ bsize = s->frame_len_bits - s->prev_block_len_bits;
+
+ s->dsp.vector_fmul_add_add(out+n, in+n, s->windows[bsize],
+ out+n, 0, block_len, 1);
+
+ memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
+ }
+
+ out += s->block_len;
+ in += s->block_len;
+
+ /* right part */
+ if (s->block_len_bits <= s->next_block_len_bits) {
+ block_len = s->block_len;
+ bsize = s->frame_len_bits - s->block_len_bits;
+
+ s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
+
+ } else {
+ block_len = 1 << s->next_block_len_bits;
+ n = (s->block_len - block_len) / 2;
+ bsize = s->frame_len_bits - s->next_block_len_bits;
+
+ memcpy(out, in, n*sizeof(float));
+
+ s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
+
+ memset(out+n+block_len, 0, n*sizeof(float));
+ }
+}
+
+
/**
* @return 0 if OK. 1 if last block of frame. return -1 if
* unrecorrable error.
@@ -657,54 +712,8 @@ static int wma_decode_block(WMACodecCont
}
}
- /* build the window : we ensure that when the windows overlap
- their squared sum is always 1 (MDCT reconstruction rule) */
- /* XXX: merge with output */
- {
- int i, next_block_len, block_len, prev_block_len, n;
- float *wptr;
-
- block_len = s->block_len;
- prev_block_len = 1 << s->prev_block_len_bits;
- next_block_len = 1 << s->next_block_len_bits;
-
- /* right part */
- wptr = s->window + block_len;
- if (block_len <= next_block_len) {
- for(i=0;i<block_len;i++)
- *wptr++ = s->windows[bsize][i];
- } else {
- /* overlap */
- n = (block_len / 2) - (next_block_len / 2);
- for(i=0;i<n;i++)
- *wptr++ = 1.0;
- for(i=0;i<next_block_len;i++)
- *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
- for(i=0;i<n;i++)
- *wptr++ = 0.0;
- }
-
- /* left part */
- wptr = s->window + block_len;
- if (block_len <= prev_block_len) {
- for(i=0;i<block_len;i++)
- *--wptr = s->windows[bsize][i];
- } else {
- /* overlap */
- n = (block_len / 2) - (prev_block_len / 2);
- for(i=0;i<n;i++)
- *--wptr = 1.0;
- for(i=0;i<prev_block_len;i++)
- *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
- for(i=0;i<n;i++)
- *--wptr = 0.0;
- }
- }
-
-
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
- float *ptr;
int n4, index, n;
n = s->block_len;
@@ -712,19 +721,14 @@ static int wma_decode_block(WMACodecCont
s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
s->output, s->coefs[ch], s->mdct_tmp);
- /* XXX: optimize all that by build the window and
- multipying/adding at the same time */
-
/* multiply by the window and add in the frame */
index = (s->frame_len / 2) + s->block_pos - n4;
- ptr = &s->frame_out[ch][index];
- s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
+ wma_window(s, &s->frame_out[ch][index]);
/* specific fast case for ms-stereo : add to second
channel if it is not coded */
if (s->ms_stereo && !s->channel_coded[1]) {
- ptr = &s->frame_out[1][index];
- s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
+ wma_window(s, &s->frame_out[1][index]);
}
}
}
@@ -779,9 +783,6 @@ static int wma_decode_frame(WMACodecCont
/* prepare for next block */
memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
s->frame_len * sizeof(float));
- /* XXX: suppress this */
- memset(&s->frame_out[ch][s->frame_len], 0,
- s->frame_len * sizeof(float));
}
#ifdef TRACE
Modified: trunk/libavcodec/wmaenc.c
==============================================================================
--- trunk/libavcodec/wmaenc.c (original)
+++ trunk/libavcodec/wmaenc.c Mon Mar 26 12:03:57 2007
@@ -92,8 +92,8 @@ static void apply_window_and_mdct(AVCode
memcpy(s->output, s->frame_out[channel], sizeof(float)*window_len);
j = channel;
for (i = 0; i < len; i++, j += avctx->channels){
- s->output[i+window_len] = audio[j] / n * win[i];
- s->frame_out[channel][i] = audio[j] / n * win[window_len - i - 1];
+ s->output[i+window_len] = audio[j] / n * win[window_len - i - 1];
+ s->frame_out[channel][i] = audio[j] / n * win[i];
}
ff_mdct_calc(&s->mdct_ctx[window_index], s->coefs[channel], s->output, s->mdct_tmp);
}
More information about the ffmpeg-cvslog
mailing list