[FFmpeg-soc] [PATCH 1/5] Use libavcodec MDCT for floating-point encoding.

[Justin Ruggles]

---
 libavcodec/ac3enc.c |   64 +++++++++++++++++++++++++++++++++++----------------
 1 files changed, 44 insertions(+), 20 deletions(-)


diff --git libavcodec/ac3enc.c libavcodec/ac3enc.c
index 1de3ee6..106cc05 100644
--- libavcodec/ac3enc.c
+++ libavcodec/ac3enc.c
@@ -96,20 +96,26 @@ typedef struct AC3EncOptions {
     /* encoding options */
 } AC3EncOptions;
 
+#if !CONFIG_FLOAT
 typedef struct IComplex {
     SampleType re,im;
 } IComplex;
+#endif
 
 typedef struct AC3MDCTContext {
     const SampleType *window;               ///< MDCT window function
     AVCodecContext *avctx;                  ///< parent context for av_log()
     int nbits;                              ///< log2(transform size)
+#if CONFIG_FLOAT
+    FFTContext fft;                         ///< FFT Context for MDCT calculation
+#else
     SampleType *costab;                     ///< FFT cos table
     SampleType *sintab;                     ///< FFT sin table
     SampleType *xcos1;                      ///< MDCT cos table
     SampleType *xsin1;                      ///< MDCT sin table
     SampleType *rot_tmp;                    ///< temp buffer for pre-rotated samples
     IComplex *cplx_tmp;                     ///< temp buffer for complex pre-rotated samples
+#endif
 } AC3MDCTContext;
 
 typedef struct AC3Block {
@@ -272,20 +278,27 @@ static const AVClass class = { "ac3", av_default_item_name, options, LIBAVUTIL_V
  */
 int exponent_group_tab[3][256];
 
+#if CONFIG_FLOAT
 static av_cold void mdct_end(AC3MDCTContext *mdct)
 {
-    mdct->nbits  = 0;
+    mdct->nbits = 0;
+    ff_mdct_end(&mdct->fft);
+    av_freep(&mdct->window);
+}
+#else
+static av_cold void mdct_end(AC3MDCTContext *mdct)
+{
+    mdct->nbits = 0;
     av_freep(&mdct->costab);
     av_freep(&mdct->sintab);
     av_freep(&mdct->xcos1);
     av_freep(&mdct->xsin1);
     av_freep(&mdct->rot_tmp);
     av_freep(&mdct->cplx_tmp);
-#if CONFIG_FLOAT
-    av_freep(&mdct->window);
-#endif
 }
+#endif
 
+#if !CONFIG_FLOAT
 static av_cold int fft_init(AC3MDCTContext *mdct, int ln)
 {
     int i, n, n2;
@@ -311,28 +324,31 @@ fft_alloc_fail:
     mdct_end(mdct);
     return AVERROR(ENOMEM);
 }
+#endif
 
-static av_cold int window_init(AC3MDCTContext *mdct)
-{
 #if CONFIG_FLOAT
+static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
+{
     SampleType *window;
+    int n = 1 << nbits;
     int n2 = (1 << mdct->nbits) >> 1;
 
+    mdct->nbits = nbits;
+
     window = av_malloc(n2 * sizeof(*window));
     if (!window)
         return AVERROR(ENOMEM);
     ff_kbd_window_init(window, 5.0, n2);
     mdct->window = window;
-#else
-    mdct->window = ff_ac3_window;
-#endif
-    return 0;
-}
 
+    return ff_mdct_init(&mdct->fft, nbits, 0, -2.0 / n);
+}
+#else
 static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
 {
-    int i, n, n2, n4;
     int ret;
+    int n = 1 << nbits;
+    int i, n2, n4;
 
     mdct->nbits = nbits;
 
@@ -340,11 +356,8 @@ static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
     if (ret)
         return ret;
 
-    ret = window_init(mdct);
-    if (ret)
-        return ret;
+    mdct->window = ff_ac3_window;
 
-    n  = 1 << nbits;
     n2 = n >> 1;
     n4 = n >> 2;
 
@@ -369,6 +382,9 @@ mdct_alloc_fail:
     mdct_end(mdct);
     return AVERROR(ENOMEM);
 }
+#endif
+
+#if !CONFIG_FLOAT
 
 /* butter fly op */
 #define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
@@ -493,6 +509,12 @@ static void calc_mdct(AC3MDCTContext *mdct, CoefType *out, SampleType *in)
         CMUL(out[n2-1-2*i], out[2*i], re, im, mdct->xsin1[i], mdct->xcos1[i]);
     }
 }
+#else /* CONFIG_FLOAT */
+static void calc_mdct(AC3MDCTContext *mdct, CoefType *out, SampleType *in)
+{
+    ff_mdct_calc(&mdct->fft, out, in);
+}
+#endif /* !CONFIG_FLOAT */
 
 #if !CONFIG_FLOAT
 /* compute log2(max(abs(tab[]))) */
@@ -534,6 +556,11 @@ static int normalize_samples(AC3EncodeContext *s)
     lshift_tab(s->windowed_samples, AC3_WINDOW_SIZE, v);
     return v - 9;
 }
+#else /* CONFIG_FLOAT */
+static int normalize_samples(AC3EncodeContext *s)
+{
+    return 0;
+}
 #endif /* !CONFIG_FLOAT */
 
 static void apply_window(SampleType *output, const SampleType *input,
@@ -563,11 +590,8 @@ static void apply_mdct(AC3EncodeContext *s)
 
             apply_window(s->windowed_samples, input_samples, s->mdct.window,
                          AC3_WINDOW_SIZE);
-#if CONFIG_FLOAT
-            s->blocks[blk].exp_shift[ch] = 0;
-#else
+
             s->blocks[blk].exp_shift[ch] = normalize_samples(s);
-#endif
 
             calc_mdct(&s->mdct, s->blocks[blk].mdct_coef[ch], s->windowed_samples);
         }

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