[FFmpeg-devel] [PATCH 1/2] avcodec: add ADPCM PSX decoder

[Paul B Mahol]

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavcodec/Makefile    |  1 +
 libavcodec/adpcm.c     | 43 +++++++++++++++++++++++++++++++++++++++++++
 libavcodec/allcodecs.c |  1 +
 libavcodec/avcodec.h   |  1 +
 4 files changed, 46 insertions(+)

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index b8bd895..f9c8501 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -686,6 +686,7 @@ OBJS-$(CONFIG_ADPCM_IMA_WAV_ENCODER)      += adpcmenc.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_IMA_WS_DECODER)       += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_MS_DECODER)           += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_MS_ENCODER)           += adpcmenc.o adpcm_data.o
+OBJS-$(CONFIG_ADPCM_PSX_DECODER)          += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_SBPRO_2_DECODER)      += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_SBPRO_3_DECODER)      += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_SBPRO_4_DECODER)      += adpcm.o adpcm_data.o
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index ba38041..904bb2b 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -152,6 +152,7 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         case AV_CODEC_ID_ADPCM_THP_LE:
         case AV_CODEC_ID_ADPCM_AFC:
         case AV_CODEC_ID_ADPCM_DTK:
+        case AV_CODEC_ID_ADPCM_PSX:
             avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
             break;
         case AV_CODEC_ID_ADPCM_IMA_WS:
@@ -665,6 +666,7 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
         nb_samples = (buf_size / 128) * 224 / ch;
         break;
     case AV_CODEC_ID_ADPCM_DTK:
+    case AV_CODEC_ID_ADPCM_PSX:
         nb_samples = buf_size / (16 * ch) * 28;
         break;
     }
@@ -1548,6 +1550,46 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
                 bytestream2_seek(&gb, 0, SEEK_SET);
         }
         break;
+    case AV_CODEC_ID_ADPCM_PSX:
+        for (channel = 0; channel < avctx->channels; channel++) {
+            samples = samples_p[channel];
+
+            /* Read in every sample for this channel.  */
+            for (i = 0; i < nb_samples / 28; i++) {
+                int predict, shift, flag;
+                int16_t byte;
+
+                predict = bytestream2_get_byteu(&gb);
+                shift   = predict & 0xf;
+                predict = predict >> 4;
+                if (predict >= 5)
+                    return AVERROR_INVALIDDATA;
+                flag    = bytestream2_get_byteu(&gb);
+
+                /* Decode 28 samples.  */
+                for (n = 0; n < 28; n++) {
+                    int32_t sample = 0;
+                    int16_t scale;
+
+                    if (flag < 0x07) {
+                        if (!(n & 1))
+                            byte = bytestream2_get_byteu(&gb);
+                        if (!(n & 1))
+                            scale = byte & 0xf;
+                        else
+                            scale = byte >> 4;
+
+                        scale = scale << 12;
+
+                        sample = (int)((scale >> shift) + c->status[channel].sample1 * xa_adpcm_table[predict][0] / 64 + c->status[channel].sample2 * xa_adpcm_table[predict][1] / 64);
+                    }
+                    *samples++ = av_clip_int16(sample);
+                    c->status[channel].sample2 = c->status[channel].sample1;
+                    c->status[channel].sample1 = sample;
+                }
+            }
+        }
+        break;
 
     default:
         return -1;
@@ -1622,6 +1664,7 @@ ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_SMJPEG,  sample_fmts_s16,  adpcm_ima_smjpeg,
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_WAV,     sample_fmts_s16p, adpcm_ima_wav,     "ADPCM IMA WAV");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_WS,      sample_fmts_both, adpcm_ima_ws,      "ADPCM IMA Westwood");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_MS,          sample_fmts_s16,  adpcm_ms,          "ADPCM Microsoft");
+ADPCM_DECODER(AV_CODEC_ID_ADPCM_PSX,         sample_fmts_s16p, adpcm_psx,         "ADPCM PSX");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_SBPRO_2,     sample_fmts_s16,  adpcm_sbpro_2,     "ADPCM Sound Blaster Pro 2-bit");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_SBPRO_3,     sample_fmts_s16,  adpcm_sbpro_3,     "ADPCM Sound Blaster Pro 2.6-bit");
 ADPCM_DECODER(AV_CODEC_ID_ADPCM_SBPRO_4,     sample_fmts_s16,  adpcm_sbpro_4,     "ADPCM Sound Blaster Pro 4-bit");
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index c8f7992..b19c9fd 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -508,6 +508,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (ADPCM_IMA_WAV,     adpcm_ima_wav);
     REGISTER_DECODER(ADPCM_IMA_WS,      adpcm_ima_ws);
     REGISTER_ENCDEC (ADPCM_MS,          adpcm_ms);
+    REGISTER_DECODER(ADPCM_PSX,         adpcm_psx);
     REGISTER_DECODER(ADPCM_SBPRO_2,     adpcm_sbpro_2);
     REGISTER_DECODER(ADPCM_SBPRO_3,     adpcm_sbpro_3);
     REGISTER_DECODER(ADPCM_SBPRO_4,     adpcm_sbpro_4);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 9b7ab3c..36f7632 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -393,6 +393,7 @@ enum AVCodecID {
     AV_CODEC_ID_ADPCM_IMA_RAD,
     AV_CODEC_ID_ADPCM_G726LE,
     AV_CODEC_ID_ADPCM_THP_LE,
+    AV_CODEC_ID_ADPCM_PSX,
 
     /* AMR */
     AV_CODEC_ID_AMR_NB = 0x12000,
-- 
1.9.1