ADPCM AFC decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>

doc/general.texi

@@ -755,6 +755,7 @@ following image formats are supported:
     @tab Used in some Sega Saturn console games.
 @item ADPCM Microsoft        @tab  X  @tab  X
 @item ADPCM MS IMA           @tab  X  @tab  X
+@item ADPCM Nintendo Gamecube AFC  @tab     @tab  X
 @item ADPCM Nintendo Gamecube THP  @tab     @tab  X
 @item ADPCM QT IMA           @tab  X  @tab  X
 @item ADPCM SEGA CRI ADX     @tab  X  @tab  X

libavcodec/Makefile

@@ -566,6 +566,7 @@ OBJS-$(CONFIG_PCM_ZORK_DECODER)           += pcm.o
 OBJS-$(CONFIG_ADPCM_4XM_DECODER)          += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_ADX_DECODER)          += adxdec.o adx.o
 OBJS-$(CONFIG_ADPCM_ADX_ENCODER)          += adxenc.o adx.o
+OBJS-$(CONFIG_ADPCM_AFC_DECODER)          += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_CT_DECODER)           += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_EA_DECODER)           += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_EA_MAXIS_XA_DECODER)  += adpcm.o adpcm_data.o

libavcodec/adpcm.c

@@ -145,6 +145,7 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         case AV_CODEC_ID_ADPCM_EA_R3:
         case AV_CODEC_ID_ADPCM_EA_XAS:
         case AV_CODEC_ID_ADPCM_THP:
+        case AV_CODEC_ID_ADPCM_AFC:
             avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
             break;
         case AV_CODEC_ID_ADPCM_IMA_WS:
@@ -575,6 +576,9 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
         *coded_samples -= *coded_samples % 14;
         nb_samples      = (buf_size - 80) / (8 * ch) * 14;
         break;
+    case AV_CODEC_ID_ADPCM_AFC:
+        nb_samples = buf_size / (9 * ch) * 16;
+        break;
     case AV_CODEC_ID_ADPCM_XA:
         nb_samples = (buf_size / 128) * 224 / ch;
         break;
@@ -1232,6 +1236,44 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
             *samples++ = adpcm_yamaha_expand_nibble(&c->status[st], v >> 4  );
         }
         break;
+    case AV_CODEC_ID_ADPCM_AFC:
+        for (channel = 0; channel < avctx->channels; channel++) {
+            int prev1 = c->status[channel].sample1;
+            int prev2 = c->status[channel].sample2;
+
+            samples = samples_p[channel];
+            /* Read in every sample for this channel.  */
+            for (i = 0; i < nb_samples / 16; i++) {
+                int byte = bytestream2_get_byteu(&gb);
+                int scale = 1 << (byte >> 4);
+                int index = byte & 0xf;
+                int factor1 = ff_adpcm_afc_coeffs[0][index];
+                int factor2 = ff_adpcm_afc_coeffs[1][index];
+
+                /* Decode 16 samples.  */
+                for (n = 0; n < 16; n++) {
+                    int32_t sampledat;
+
+                    if (n & 1) {
+                        sampledat = sign_extend(byte, 4);
+                    } else {
+                        byte = bytestream2_get_byteu(&gb);
+                        sampledat = sign_extend(byte >> 4, 4);
+                    }
+
+                    sampledat = ((prev1 * factor1 + prev2 * factor2) +
+                                 ((sampledat * scale) << 11)) >> 11;
+                    *samples = av_clip_int16(sampledat);
+                    prev2 = prev1;
+                    prev1 = *samples++;
+                }
+            }
+
+            c->status[channel].sample1 = prev1;
+            c->status[channel].sample2 = prev2;
+        }
+        bytestream2_seek(&gb, 0, SEEK_END);
+        break;
     case AV_CODEC_ID_ADPCM_THP:
     {
         int table[2][16];
@@ -1314,6 +1356,7 @@ AVCodec ff_ ## name_ ## _decoder = {                        \
 
 /* Note: Do not forget to add new entries to the Makefile as well. */
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_4XM,         sample_fmts_s16p, adpcm_4xm,         "ADPCM 4X Movie");
+ADPCM_DECODER(AV_CODEC_ID_ADPCM_AFC,         sample_fmts_s16p, adpcm_afc,         "ADPCM Nintendo Gamecube AFC");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_CT,          sample_fmts_s16,  adpcm_ct,          "ADPCM Creative Technology");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_EA,          sample_fmts_s16,  adpcm_ea,          "ADPCM Electronic Arts");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_EA_MAXIS_XA, sample_fmts_s16,  adpcm_ea_maxis_xa, "ADPCM Electronic Arts Maxis CDROM XA");

libavcodec/adpcm_data.c

@@ -76,3 +76,8 @@ const int8_t ff_adpcm_yamaha_difflookup[] = {
      1,  3,  5,  7,  9,  11,  13,  15,
     -1, -3, -5, -7, -9, -11, -13, -15
 };
+
+const int16_t ff_adpcm_afc_coeffs[2][16] = {
+    { 0, 2048, 0, 1024, 4096, 3584, 3072, 4608, 4200, 4800, 5120, 2048, 1024, 64512, 64512, 63488 },
+    { 0, 0, 2048, 1024, 63488, 64000, 64512, 62976, 63288, 63236, 62464, 63488, 64512, 1024, 0, 0 }
+};

libavcodec/adpcm_data.h

@@ -35,5 +35,6 @@ extern const uint8_t ff_adpcm_AdaptCoeff1[];
 extern const int8_t  ff_adpcm_AdaptCoeff2[];
 extern const int16_t ff_adpcm_yamaha_indexscale[];
 extern const int8_t  ff_adpcm_yamaha_difflookup[];
+extern const int16_t ff_adpcm_afc_coeffs[2][16];
 
 #endif /* AVCODEC_ADPCM_DATA_H */

libavcodec/allcodecs.c

@@ -387,6 +387,7 @@ void avcodec_register_all(void)
     /* ADPCM codecs */
     REGISTER_DECODER (ADPCM_4XM, adpcm_4xm);
     REGISTER_ENCDEC  (ADPCM_ADX, adpcm_adx);
+    REGISTER_DECODER (ADPCM_AFC, adpcm_afc);
     REGISTER_DECODER (ADPCM_CT, adpcm_ct);
     REGISTER_DECODER (ADPCM_EA, adpcm_ea);
     REGISTER_DECODER (ADPCM_EA_MAXIS_XA, adpcm_ea_maxis_xa);

libavcodec/avcodec.h

@@ -352,6 +352,7 @@ enum AVCodecID {
     AV_CODEC_ID_ADPCM_G722,
     AV_CODEC_ID_ADPCM_IMA_APC,
     AV_CODEC_ID_VIMA       = MKBETAG('V','I','M','A'),
+    AV_CODEC_ID_ADPCM_AFC  = MKBETAG('A','F','C',' '),
 
     /* AMR */
     AV_CODEC_ID_AMR_NB = 0x12000,

libavcodec/codec_desc.c

@@ -1756,6 +1756,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("ADPCM IMA CRYO APC"),
         .props     = AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_ADPCM_AFC,
+        .type      = AVMEDIA_TYPE_AUDIO,
+        .name      = "adpcm_afc",
+        .long_name = NULL_IF_CONFIG_SMALL("ADPCM Nintendo Gamecube AFC"),
+        .props     = AV_CODEC_PROP_LOSSY,
+    },
 
     /* AMR */
     {

libavcodec/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR 75
+#define LIBAVCODEC_VERSION_MINOR 76
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavformat/ast.c

@@ -43,6 +43,9 @@ static int ast_read_header(AVFormatContext *s)
     avio_skip(s->pb, 8);
     codec = avio_rb16(s->pb);
     switch (codec) {
+    case 0:
+        st->codec->codec_id = AV_CODEC_ID_ADPCM_AFC;
+        break;
     case 1:
         st->codec->codec_id = AV_CODEC_ID_PCM_S16BE_PLANAR;
         break;