dcadec: simplify decoding of VQ high frequencies

The vector dequantization has a test in a loop preventing effective SIMD
implementation. By moving it out of the loop, this loop can be DSPized.

Therefore, modify the current DSP implementation. In particular, the
DSP implementation no longer has to handle null loop sizes.

The decode_hf implementations have following timings:

For x86 Arrandale:
        C  SSE SSE2 SSE4
win32: 260 162  119  104
win64: 242 N/A   89   72

The arm NEON optimizations follow in a later patch as external asm. The
now unused check for the y modifier in arm inline asm is removed from
configure.

1 files changed, 7 insertions, 23 deletions

diff --git a/libavcodec/dcadec.c b/libavcodec/dcadec.c
index 5ede61db33..92edce7e42 100644
--- a/libavcodec/dcadec.c
+++ b/libavcodec/dcadec.c
@@ -50,14 +50,10 @@
 #if ARCH_ARM
 #   include "arm/dca.h"
 #endif
-#if ARCH_X86
-#   include "x86/dca.h"
-#endif
 
 //#define TRACE
 
 #define DCA_PRIM_CHANNELS_MAX  (7)
-#define DCA_SUBBANDS          (32)
 #define DCA_ABITS_MAX         (32)      /* Should be 28 */
 #define DCA_SUBSUBFRAMES_MAX   (4)
 #define DCA_SUBFRAMES_MAX     (16)
@@ -340,7 +336,7 @@ typedef struct {
     int prediction_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];      ///< prediction VQ coefs
     int bitalloc[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];           ///< bit allocation index
     int transition_mode[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];    ///< transition mode (transients)
-    int scale_factor[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][2];    ///< scale factors (2 if transient)
+    int32_t scale_factor[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][2];///< scale factors (2 if transient)
     int joint_huff[DCA_PRIM_CHANNELS_MAX];                       ///< joint subband scale factors codebook
     int joint_scale_factor[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS]; ///< joint subband scale factors
     float downmix_coef[DCA_PRIM_CHANNELS_MAX + 1][2];            ///< stereo downmix coefficients
@@ -353,7 +349,7 @@ typedef struct {
     uint8_t  core_downmix_amode;                                 ///< audio channel arrangement of embedded downmix
     uint16_t core_downmix_codes[DCA_PRIM_CHANNELS_MAX + 1][4];   ///< embedded downmix coefficients (9-bit codes)
 
-    int high_freq_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];       ///< VQ encoded high frequency subbands
+    int32_t  high_freq_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];  ///< VQ encoded high frequency subbands
 
     float lfe_data[2 * DCA_LFE_MAX * (DCA_BLOCKS_MAX + 4)];      ///< Low frequency effect data
     int lfe_scale_factor;
@@ -1088,14 +1084,6 @@ static int decode_blockcodes(int code1, int code2, int levels, int32_t *values)
 static const uint8_t abits_sizes[7]  = { 7, 10, 12, 13, 15, 17, 19 };
 static const uint8_t abits_levels[7] = { 3,  5,  7,  9, 13, 17, 25 };
 
-#ifndef int8x8_fmul_int32
-static inline void int8x8_fmul_int32(DCADSPContext *dsp, float *dst,
-                                     const int8_t *src, int scale)
-{
-    dsp->int8x8_fmul_int32(dst, src, scale);
-}
-#endif
-
 static int dca_subsubframe(DCAContext *s, int base_channel, int block_index)
 {
     int k, l;
@@ -1220,20 +1208,16 @@ static int dca_subsubframe(DCAContext *s, int base_channel, int block_index)
         /*
          * Decode VQ encoded high frequencies
          */
-        for (l = s->vq_start_subband[k]; l < s->subband_activity[k]; l++) {
-            /* 1 vector -> 32 samples but we only need the 8 samples
-             * for this subsubframe. */
-            int hfvq = s->high_freq_vq[k][l];
-
+        if (s->subband_activity[k] > s->vq_start_subband[k]) {
             if (!s->debug_flag & 0x01) {
                 av_log(s->avctx, AV_LOG_DEBUG,
                        "Stream with high frequencies VQ coding\n");
                 s->debug_flag |= 0x01;
             }
-
-            int8x8_fmul_int32(&s->dcadsp, subband_samples[k][l],
-                              &high_freq_vq[hfvq][subsubframe * 8],
-                              s->scale_factor[k][l][0]);
+            s->dcadsp.decode_hf(subband_samples[k], s->high_freq_vq[k],
+                                high_freq_vq, subsubframe * 8,
+                                s->scale_factor[k], s->vq_start_subband[k],
+                                s->subband_activity[k]);
         }
     }