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AC-3 decoder, soc revision 57, Aug 19 12:44:38 2006 UTC by cloud9

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Optimization as suggested by Benjamin.

Originally committed as revision 9665 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2007-07-14 16:02:08 +00:00
parent 032732d49d
commit 1d0a6f5209
1 changed files with 17 additions and 5 deletions
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22
libavcodec/ac3dec.c
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@ -171,6 +171,7 @@ typedef struct {
/* For IMDCT. */
MDCTContext imdct_512; //N/8 point IFFT context
MDCTContext imdct_256; //N/4 point IFFT context
DSPContext dsp; //for optimization
DECLARE_ALIGNED_16(float, output[MAX_CHANNELS][BLOCK_SIZE]);
DECLARE_ALIGNED_16(float, delay[MAX_CHANNELS][BLOCK_SIZE]);
DECLARE_ALIGNED_16(float, tmp_imdct[BLOCK_SIZE]);
@ -397,6 +398,7 @@ static int ac3_decode_init(AVCodecContext *avctx)
ac3_tables_init();
ff_mdct_init(&ctx->imdct_256, 8, 1);
ff_mdct_init(&ctx->imdct_512, 9, 1);
dsputil_init(&ctx->dsp, avctx);
dither_seed(&ctx->dith_state, 0);
return 0;
@ -1566,6 +1568,7 @@ static void do_imdct_256(AC3DecodeContext *ctx, int chindex)
{
int k;
float x1[128], x2[128];
float *ptr;
for (k = 0; k < N / 4; k++) {
x1[k] = ctx->transform_coeffs[chindex][2 * k];
@ -1575,27 +1578,36 @@ static void do_imdct_256(AC3DecodeContext *ctx, int chindex)
ff_imdct_calc(&ctx->imdct_256, ctx->tmp_output, x1, ctx->tmp_imdct);
ff_imdct_calc(&ctx->imdct_256, ctx->tmp_output + 256, x2, ctx->tmp_imdct);
for (k = 0; k < N / 2; k++) {
ptr = ctx->output[chindex];
ctx->dsp.vector_fmul_add_add(ptr, ctx->tmp_output, window, ctx->delay[chindex], 0, BLOCK_SIZE, 1);
ptr = ctx->delay[chindex];
ctx->dsp.vector_fmul_reverse(ptr, ctx->tmp_output + 256, window, BLOCK_SIZE);
/*for (k = 0; k < N / 2; k++) {
ctx->output[chindex][k] = ctx->tmp_output[k] * window[k] + ctx->delay[chindex][k];
//dump_floats("samples", 10, ctx->output[chindex], 256);
ctx->delay[chindex][k] = ctx->tmp_output[N / 2 + k] * window[255 - k];
}
}*/
}
static void do_imdct_512(AC3DecodeContext *ctx, int chindex)
{
int k;
//int k;
float *ptr;
ff_imdct_calc(&ctx->imdct_512, ctx->tmp_output,
ctx->transform_coeffs[chindex], ctx->tmp_imdct);
//ff_imdct_calc_ac3_512(&ctx->imdct_512, ctx->tmp_output, ctx->transform_coeffs[chindex],
// ctx->tmp_imdct, window);
ptr = ctx->output[chindex];
ctx->dsp.vector_fmul_add_add(ptr, ctx->tmp_output, window, ctx->delay[chindex], 0, BLOCK_SIZE, 1);
ptr = ctx->delay[chindex];
ctx->dsp.vector_fmul_reverse(ptr, ctx->tmp_output + 256, window, BLOCK_SIZE);
for (k = 0; k < N / 2; k++) {
/*for (k = 0; k < N / 2; k++) {
ctx->output[chindex][k] = ctx->tmp_output[k] * window[k] + ctx->delay[chindex][k];
//dump_floats("samples", 10, ctx->output[chindex], 256);
ctx->delay[chindex][k] = ctx->tmp_output[N / 2 + k] * window[255 - k];
}
} */
}
static inline void do_imdct(AC3DecodeContext *ctx)