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@@ -26,54 +26,17 @@
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* fixed-point AC-3 encoder.
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*/
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+#define CONFIG_FFT_FLOAT 0
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#undef CONFIG_AC3ENC_FLOAT
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#include "ac3enc.c"
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-/** Scale a float value by 2^15, convert to an integer, and clip to range -32767..32767. */
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-#define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
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-
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-
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/**
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* Finalize MDCT and free allocated memory.
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*/
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static av_cold void mdct_end(AC3MDCTContext *mdct)
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{
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- mdct->nbits = 0;
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- av_freep(&mdct->costab);
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- av_freep(&mdct->sintab);
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- av_freep(&mdct->xcos1);
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- av_freep(&mdct->xsin1);
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- av_freep(&mdct->rot_tmp);
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- av_freep(&mdct->cplx_tmp);
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-}
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-
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-
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-/**
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- * Initialize FFT tables.
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- * @param ln log2(FFT size)
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- */
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-static av_cold int fft_init(AVCodecContext *avctx, AC3MDCTContext *mdct, int ln)
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-{
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- int i, n, n2;
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- float alpha;
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-
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- n = 1 << ln;
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- n2 = n >> 1;
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-
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- FF_ALLOC_OR_GOTO(avctx, mdct->costab, n2 * sizeof(*mdct->costab), fft_alloc_fail);
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- FF_ALLOC_OR_GOTO(avctx, mdct->sintab, n2 * sizeof(*mdct->sintab), fft_alloc_fail);
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-
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- for (i = 0; i < n2; i++) {
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- alpha = 2.0 * M_PI * i / n;
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- mdct->costab[i] = FIX15(cos(alpha));
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- mdct->sintab[i] = FIX15(sin(alpha));
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- }
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-
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- return 0;
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-fft_alloc_fail:
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- mdct_end(mdct);
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- return AVERROR(ENOMEM);
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+ ff_fft_end(&mdct->fft);
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}
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@@ -84,167 +47,9 @@ fft_alloc_fail:
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static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct,
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int nbits)
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{
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- int i, n, n4, ret;
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-
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- n = 1 << nbits;
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- n4 = n >> 2;
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-
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- mdct->nbits = nbits;
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-
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- ret = fft_init(avctx, mdct, nbits - 2);
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- if (ret)
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- return ret;
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-
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+ int ret = ff_mdct_init(&mdct->fft, nbits, 0, 1.0);
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mdct->window = ff_ac3_window;
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-
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- FF_ALLOC_OR_GOTO(avctx, mdct->xcos1, n4 * sizeof(*mdct->xcos1), mdct_alloc_fail);
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- FF_ALLOC_OR_GOTO(avctx, mdct->xsin1, n4 * sizeof(*mdct->xsin1), mdct_alloc_fail);
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- FF_ALLOC_OR_GOTO(avctx, mdct->rot_tmp, n * sizeof(*mdct->rot_tmp), mdct_alloc_fail);
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- FF_ALLOC_OR_GOTO(avctx, mdct->cplx_tmp, n4 * sizeof(*mdct->cplx_tmp), mdct_alloc_fail);
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-
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- for (i = 0; i < n4; i++) {
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- float alpha = 2.0 * M_PI * (i + 1.0 / 8.0) / n;
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- mdct->xcos1[i] = FIX15(-cos(alpha));
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- mdct->xsin1[i] = FIX15(-sin(alpha));
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- }
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-
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- return 0;
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-mdct_alloc_fail:
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- mdct_end(mdct);
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- return AVERROR(ENOMEM);
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-}
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-
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-
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-/** Butterfly op */
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-#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
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-{ \
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- int ax, ay, bx, by; \
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- bx = pre1; \
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- by = pim1; \
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- ax = qre1; \
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- ay = qim1; \
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- pre = (bx + ax) >> 1; \
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- pim = (by + ay) >> 1; \
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- qre = (bx - ax) >> 1; \
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- qim = (by - ay) >> 1; \
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-}
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-
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-
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-/** Complex multiply */
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-#define CMUL(pre, pim, are, aim, bre, bim, rshift) \
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-{ \
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- pre = (MUL16(are, bre) - MUL16(aim, bim)) >> rshift; \
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- pim = (MUL16(are, bim) + MUL16(bre, aim)) >> rshift; \
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-}
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-
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-
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-/**
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- * Calculate a 2^n point complex FFT on 2^ln points.
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- * @param z complex input/output samples
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- * @param ln log2(FFT size)
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- */
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-static void fft(AC3MDCTContext *mdct, IComplex *z, int ln)
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-{
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- int j, l, np, np2;
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- int nblocks, nloops;
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- register IComplex *p,*q;
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- int tmp_re, tmp_im;
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-
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- np = 1 << ln;
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-
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- /* reverse */
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- for (j = 0; j < np; j++) {
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- int k = av_reverse[j] >> (8 - ln);
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- if (k < j)
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- FFSWAP(IComplex, z[k], z[j]);
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- }
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-
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- /* pass 0 */
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-
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- p = &z[0];
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- j = np >> 1;
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- do {
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- BF(p[0].re, p[0].im, p[1].re, p[1].im,
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- p[0].re, p[0].im, p[1].re, p[1].im);
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- p += 2;
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- } while (--j);
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-
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- /* pass 1 */
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-
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- p = &z[0];
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- j = np >> 2;
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- do {
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- BF(p[0].re, p[0].im, p[2].re, p[2].im,
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- p[0].re, p[0].im, p[2].re, p[2].im);
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- BF(p[1].re, p[1].im, p[3].re, p[3].im,
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- p[1].re, p[1].im, p[3].im, -p[3].re);
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- p+=4;
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- } while (--j);
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-
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- /* pass 2 .. ln-1 */
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-
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- nblocks = np >> 3;
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- nloops = 1 << 2;
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- np2 = np >> 1;
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- do {
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- p = z;
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- q = z + nloops;
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- for (j = 0; j < nblocks; j++) {
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- BF(p->re, p->im, q->re, q->im,
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- p->re, p->im, q->re, q->im);
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- p++;
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- q++;
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- for(l = nblocks; l < np2; l += nblocks) {
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- CMUL(tmp_re, tmp_im, mdct->costab[l], -mdct->sintab[l], q->re, q->im, 15);
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- BF(p->re, p->im, q->re, q->im,
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- p->re, p->im, tmp_re, tmp_im);
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- p++;
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- q++;
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- }
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- p += nloops;
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- q += nloops;
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- }
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- nblocks = nblocks >> 1;
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- nloops = nloops << 1;
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- } while (nblocks);
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-}
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-
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-
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-/**
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- * Calculate a 512-point MDCT
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- * @param out 256 output frequency coefficients
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- * @param in 512 windowed input audio samples
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- */
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-static void mdct512(AC3MDCTContext *mdct, int32_t *out, int16_t *in)
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-{
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- int i, re, im, n, n2, n4;
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- int16_t *rot = mdct->rot_tmp;
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- IComplex *x = mdct->cplx_tmp;
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-
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- n = 1 << mdct->nbits;
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- n2 = n >> 1;
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- n4 = n >> 2;
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-
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- /* shift to simplify computations */
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- for (i = 0; i <n4; i++)
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- rot[i] = -in[i + 3*n4];
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- memcpy(&rot[n4], &in[0], 3*n4*sizeof(*in));
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-
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- /* pre rotation */
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- for (i = 0; i < n4; i++) {
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- re = ((int)rot[ 2*i] - (int)rot[ n-1-2*i]) >> 1;
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- im = -((int)rot[n2+2*i] - (int)rot[n2-1-2*i]) >> 1;
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- CMUL(x[i].re, x[i].im, re, im, -mdct->xcos1[i], mdct->xsin1[i], 15);
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- }
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-
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- fft(mdct, x, mdct->nbits - 2);
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-
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- /* post rotation */
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- for (i = 0; i < n4; i++) {
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- re = x[i].re;
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- im = x[i].im;
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- CMUL(out[n2-1-2*i], out[2*i], re, im, mdct->xsin1[i], mdct->xcos1[i], 0);
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- }
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+ return ret;
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}
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@@ -304,101 +109,6 @@ static void scale_coefficients(AC3EncodeContext *s)
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}
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-#ifdef TEST
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-/*************************************************************************/
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-/* TEST */
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-
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-#include "libavutil/lfg.h"
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-
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-#define MDCT_NBITS 9
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-#define MDCT_SAMPLES (1 << MDCT_NBITS)
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-#define FN (MDCT_SAMPLES/4)
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-
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-
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-static void fft_test(AC3MDCTContext *mdct, AVLFG *lfg)
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-{
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- IComplex in[FN], in1[FN];
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- int k, n, i;
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- float sum_re, sum_im, a;
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-
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- for (i = 0; i < FN; i++) {
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- in[i].re = av_lfg_get(lfg) % 65535 - 32767;
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- in[i].im = av_lfg_get(lfg) % 65535 - 32767;
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- in1[i] = in[i];
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- }
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- fft(mdct, in, 7);
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-
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- /* do it by hand */
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- for (k = 0; k < FN; k++) {
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- sum_re = 0;
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- sum_im = 0;
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- for (n = 0; n < FN; n++) {
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- a = -2 * M_PI * (n * k) / FN;
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- sum_re += in1[n].re * cos(a) - in1[n].im * sin(a);
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- sum_im += in1[n].re * sin(a) + in1[n].im * cos(a);
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- }
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- av_log(NULL, AV_LOG_DEBUG, "%3d: %6d,%6d %6.0f,%6.0f\n",
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- k, in[k].re, in[k].im, sum_re / FN, sum_im / FN);
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- }
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-}
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-
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-
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-static void mdct_test(AC3MDCTContext *mdct, AVLFG *lfg)
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-{
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- int16_t input[MDCT_SAMPLES];
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- int32_t output[AC3_MAX_COEFS];
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- float input1[MDCT_SAMPLES];
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- float output1[AC3_MAX_COEFS];
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- float s, a, err, e, emax;
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- int i, k, n;
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-
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- for (i = 0; i < MDCT_SAMPLES; i++) {
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- input[i] = (av_lfg_get(lfg) % 65535 - 32767) * 9 / 10;
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- input1[i] = input[i];
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- }
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-
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- mdct512(mdct, output, input);
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-
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- /* do it by hand */
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- for (k = 0; k < AC3_MAX_COEFS; k++) {
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- s = 0;
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- for (n = 0; n < MDCT_SAMPLES; n++) {
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- a = (2*M_PI*(2*n+1+MDCT_SAMPLES/2)*(2*k+1) / (4 * MDCT_SAMPLES));
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- s += input1[n] * cos(a);
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- }
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- output1[k] = -2 * s / MDCT_SAMPLES;
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- }
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-
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- err = 0;
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- emax = 0;
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- for (i = 0; i < AC3_MAX_COEFS; i++) {
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- av_log(NULL, AV_LOG_DEBUG, "%3d: %7d %7.0f\n", i, output[i], output1[i]);
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- e = output[i] - output1[i];
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- if (e > emax)
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- emax = e;
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- err += e * e;
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- }
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- av_log(NULL, AV_LOG_DEBUG, "err2=%f emax=%f\n", err / AC3_MAX_COEFS, emax);
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-}
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-
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-
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-int main(void)
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-{
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- AVLFG lfg;
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- AC3MDCTContext mdct;
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-
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- mdct.avctx = NULL;
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- av_log_set_level(AV_LOG_DEBUG);
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- mdct_init(&mdct, 9);
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-
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- fft_test(&mdct, &lfg);
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- mdct_test(&mdct, &lfg);
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-
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- return 0;
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-}
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-#endif /* TEST */
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-
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-
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AVCodec ff_ac3_fixed_encoder = {
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"ac3_fixed",
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AVMEDIA_TYPE_AUDIO,
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Michael Niedermayer