From 3a7f5d072a7786c841d7c357c3ed97173736752f Mon Sep 17 00:00:00 2001
From: Vitor Sessak <vitor1001@gmail.com>
Date: Thu, 27 Sep 2007 06:21:57 +0000
Subject: [PATCH] AMV audio decoder

Originally committed as revision 10598 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/Makefile    |  1 +
 libavcodec/adpcm.c     | 17 +++++++++++++++--
 libavcodec/allcodecs.c |  1 +
 libavcodec/avcodec.h   |  1 +
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 505b1beb2e..daca9b90bb 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -263,6 +263,7 @@ OBJS-$(CONFIG_ADPCM_EA_DECODER)        += adpcm.o
 OBJS-$(CONFIG_ADPCM_EA_ENCODER)        += adpcm.o
 OBJS-$(CONFIG_ADPCM_G726_DECODER)      += g726.o
 OBJS-$(CONFIG_ADPCM_G726_ENCODER)      += g726.o
+OBJS-$(CONFIG_ADPCM_IMA_AMV_DECODER)   += adpcm.o
 OBJS-$(CONFIG_ADPCM_IMA_DK3_DECODER)   += adpcm.o
 OBJS-$(CONFIG_ADPCM_IMA_DK3_ENCODER)   += adpcm.o
 OBJS-$(CONFIG_ADPCM_IMA_DK4_DECODER)   += adpcm.o
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 2329f9af89..0d1e0ecd55 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -1182,16 +1182,28 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
             }
         }
         break;
+    case CODEC_ID_ADPCM_IMA_AMV:
     case CODEC_ID_ADPCM_IMA_SMJPEG:
         c->status[0].predictor = *src;
         src += 2;
         c->status[0].step_index = *src++;
         src++;  /* skip another byte before getting to the meat */
+
+        if (avctx->codec->id == CODEC_ID_ADPCM_IMA_AMV)
+            src+=4;
+
         while (src < buf + buf_size) {
+            char hi, lo;
+            lo = *src & 0x0F;
+            hi = (*src >> 4) & 0x0F;
+
+            if (avctx->codec->id == CODEC_ID_ADPCM_IMA_AMV)
+                FFSWAP(char, hi, lo);
+
             *samples++ = adpcm_ima_expand_nibble(&c->status[0],
-                *src & 0x0F, 3);
+                lo, 3);
             *samples++ = adpcm_ima_expand_nibble(&c->status[0],
-                (*src >> 4) & 0x0F, 3);
+                hi, 3);
             src++;
         }
         break;
@@ -1439,6 +1451,7 @@ ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)
 ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
 ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);
 ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);
+ADPCM_CODEC(CODEC_ID_ADPCM_IMA_AMV, adpcm_ima_amv);
 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);
 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);
 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 6c6ad3be09..bd566a51fa 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -246,6 +246,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC  (ADPCM_CT, adpcm_ct);
     REGISTER_ENCDEC  (ADPCM_EA, adpcm_ea);
     REGISTER_ENCDEC  (ADPCM_G726, adpcm_g726);
+    REGISTER_DECODER (ADPCM_IMA_AMV, adpcm_ima_amv);
     REGISTER_ENCDEC  (ADPCM_IMA_DK3, adpcm_ima_dk3);
     REGISTER_ENCDEC  (ADPCM_IMA_DK4, adpcm_ima_dk4);
     REGISTER_ENCDEC  (ADPCM_IMA_QT, adpcm_ima_qt);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index a8b447e27b..638b42d2ea 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -208,6 +208,7 @@ enum CodecID {
     CODEC_ID_ADPCM_SBPRO_3,
     CODEC_ID_ADPCM_SBPRO_2,
     CODEC_ID_ADPCM_THP,
+    CODEC_ID_ADPCM_IMA_AMV,
 
     /* AMR */
     CODEC_ID_AMR_NB= 0x12000,