1 files changed, 216 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/demac/libdemac/decoder.c b/lib/rbcodec/codecs/demac/libdemac/decoder.c
new file mode 100644
index 0000000000..b0339a75d9
--- /dev/null
+++ b/lib/rbcodec/codecs/demac/libdemac/decoder.c
@@ -0,0 +1,216 @@
+/*
+
+libdemac - A Monkey's Audio decoder
+
+$Id$
+
+Copyright (C) Dave Chapman 2007
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
+
+*/
+
+#include <inttypes.h>
+#include <string.h>
+
+#include "demac.h"
+#include "predictor.h"
+#include "entropy.h"
+#include "filter.h"
+#include "demac_config.h"
+
+/* Statically allocate the filter buffers */
+
+#ifdef FILTER256_IRAM
+static filter_int filterbuf32[(32*3 + FILTER_HISTORY_SIZE) * 2]   
+                  IBSS_ATTR_DEMAC MEM_ALIGN_ATTR; 
+                  /* 2432 or 4864 bytes */
+static filter_int filterbuf256[(256*3 + FILTER_HISTORY_SIZE) * 2]
+                  IBSS_ATTR_DEMAC MEM_ALIGN_ATTR; 
+                  /* 5120 or 10240 bytes */
+#define FILTERBUF64 filterbuf256
+#define FILTERBUF32 filterbuf32
+#define FILTERBUF16 filterbuf32
+#else
+static filter_int filterbuf64[(64*3 + FILTER_HISTORY_SIZE) * 2]   
+                  IBSS_ATTR_DEMAC MEM_ALIGN_ATTR; 
+                  /* 2432 or 4864 bytes */
+static filter_int filterbuf256[(256*3 + FILTER_HISTORY_SIZE) * 2]
+                  MEM_ALIGN_ATTR; /* 5120 or 10240 bytes */
+#define FILTERBUF64 filterbuf64
+#define FILTERBUF32 filterbuf64
+#define FILTERBUF16 filterbuf64
+#endif
+
+/* This is only needed for "insane" files, and no current Rockbox targets
+   can hope to decode them in realtime, except the Gigabeat S (at 528MHz). */
+static filter_int filterbuf1280[(1280*3 + FILTER_HISTORY_SIZE) * 2] 
+                  IBSS_ATTR_DEMAC_INSANEBUF MEM_ALIGN_ATTR;
+                  /* 17408 or 34816 bytes */
+
+void init_frame_decoder(struct ape_ctx_t* ape_ctx,
+                        unsigned char* inbuffer, int* firstbyte,
+                        int* bytesconsumed)
+{
+    init_entropy_decoder(ape_ctx, inbuffer, firstbyte, bytesconsumed);
+    //printf("CRC=0x%08x\n",ape_ctx->CRC);
+    //printf("Flags=0x%08x\n",ape_ctx->frameflags);
+
+    init_predictor_decoder(&ape_ctx->predictor);
+
+    switch (ape_ctx->compressiontype)
+    {
+        case 2000:
+            init_filter_16_11(FILTERBUF16);
+            break;
+
+        case 3000:
+            init_filter_64_11(FILTERBUF64);
+            break;
+
+        case 4000:
+            init_filter_256_13(filterbuf256);
+            init_filter_32_10(FILTERBUF32);
+            break;
+
+        case 5000:
+            init_filter_1280_15(filterbuf1280);
+            init_filter_256_13(filterbuf256);
+            init_filter_16_11(FILTERBUF32);
+    }
+}
+
+int ICODE_ATTR_DEMAC decode_chunk(struct ape_ctx_t* ape_ctx,
+                                  unsigned char* inbuffer, int* firstbyte,
+                                  int* bytesconsumed,
+                                  int32_t* decoded0, int32_t* decoded1,
+                                  int count)
+{
+    int32_t left, right;
+#ifdef ROCKBOX
+    int scale = (APE_OUTPUT_DEPTH - ape_ctx->bps);
+    #define SCALE(x) ((x) << scale)
+#else
+    #define SCALE(x) (x)
+#endif
+         
+    if ((ape_ctx->channels==1) || ((ape_ctx->frameflags
+        & (APE_FRAMECODE_PSEUDO_STEREO|APE_FRAMECODE_STEREO_SILENCE))
+        == APE_FRAMECODE_PSEUDO_STEREO)) {
+
+        entropy_decode(ape_ctx, inbuffer, firstbyte, bytesconsumed,
+                       decoded0, NULL, count);
+
+        if (ape_ctx->frameflags & APE_FRAMECODE_MONO_SILENCE) {
+            /* We are pure silence, so we're done. */
+            return 0;
+        }
+
+        switch (ape_ctx->compressiontype)
+        {
+            case 2000:
+                apply_filter_16_11(ape_ctx->fileversion,0,decoded0,count);
+                break;
+    
+            case 3000:
+                apply_filter_64_11(ape_ctx->fileversion,0,decoded0,count);
+                break;
+    
+            case 4000:
+                apply_filter_32_10(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_256_13(ape_ctx->fileversion,0,decoded0,count);
+                break;
+    
+            case 5000:
+                apply_filter_16_11(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_256_13(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_1280_15(ape_ctx->fileversion,0,decoded0,count);
+        }
+
+        /* Now apply the predictor decoding */
+        predictor_decode_mono(&ape_ctx->predictor,decoded0,count);
+
+        if (ape_ctx->channels==2) {
+            /* Pseudo-stereo - copy left channel to right channel */
+            while (count--)
+            {
+                left = *decoded0;
+                *(decoded1++) = *(decoded0++) = SCALE(left);
+            }
+        }
+#ifdef ROCKBOX
+         else {
+            /* Scale to output depth */
+            while (count--)
+            {
+                left = *decoded0;
+                *(decoded0++) = SCALE(left);
+            }
+        }
+#endif
+    } else { /* Stereo */
+        entropy_decode(ape_ctx, inbuffer, firstbyte, bytesconsumed,
+                       decoded0, decoded1, count);
+
+        if ((ape_ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE)
+            == APE_FRAMECODE_STEREO_SILENCE) {
+            /* We are pure silence, so we're done. */
+            return 0;
+        }
+
+        /* Apply filters - compression type 1000 doesn't have any */
+        switch (ape_ctx->compressiontype)
+        {
+            case 2000:
+                apply_filter_16_11(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_16_11(ape_ctx->fileversion,1,decoded1,count);
+                break;
+    
+            case 3000:
+                apply_filter_64_11(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_64_11(ape_ctx->fileversion,1,decoded1,count);
+                break;
+    
+            case 4000:
+                apply_filter_32_10(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_32_10(ape_ctx->fileversion,1,decoded1,count);
+                apply_filter_256_13(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_256_13(ape_ctx->fileversion,1,decoded1,count);
+                break;
+    
+            case 5000:
+                apply_filter_16_11(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_16_11(ape_ctx->fileversion,1,decoded1,count);
+                apply_filter_256_13(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_256_13(ape_ctx->fileversion,1,decoded1,count);
+                apply_filter_1280_15(ape_ctx->fileversion,0,decoded0,count);
+                apply_filter_1280_15(ape_ctx->fileversion,1,decoded1,count);
+        }
+
+        /* Now apply the predictor decoding */
+        predictor_decode_stereo(&ape_ctx->predictor,decoded0,decoded1,count);
+
+        /* Decorrelate and scale to output depth */
+        while (count--)
+        {
+            left = *decoded1 - (*decoded0 / 2);
+            right = left + *decoded0;
+
+            *(decoded0++) = SCALE(left);
+            *(decoded1++) = SCALE(right);
+        }
+    }
+    return 0;
+}