From a11c2a2c66c6e74f4af366995704a3819466f3a8 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Mon, 30 Jul 2007 02:05:16 +0000
Subject: [PATCH] support silly PCM variant used by zork nemesis fixes audio
 decoding of T000A11C.AVI

Originally committed as revision 9831 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/allcodecs.c |  1 +
 libavcodec/allcodecs.h |  1 +
 libavcodec/avcodec.h   |  1 +
 libavcodec/pcm.c       | 18 ++++++++++++++++++
 libavformat/riff.c     |  2 ++
 5 files changed, 23 insertions(+)

diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 8153e416ce..6a944e14ae 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -225,6 +225,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (PCM_U24LE, pcm_u24le);
     REGISTER_ENCDEC (PCM_U32BE, pcm_u32be);
     REGISTER_ENCDEC (PCM_U32LE, pcm_u32le);
+    REGISTER_ENCDEC (PCM_ZORK , pcm_zork);
 
     /* dpcm codecs */
     REGISTER_DECODER(INTERPLAY_DPCM, interplay_dpcm);
diff --git a/libavcodec/allcodecs.h b/libavcodec/allcodecs.h
index 3e18ca0d41..98721ace5c 100644
--- a/libavcodec/allcodecs.h
+++ b/libavcodec/allcodecs.h
@@ -228,6 +228,7 @@ PCM_CODEC(CODEC_ID_PCM_U24BE,   pcm_u24be);
 PCM_CODEC(CODEC_ID_PCM_U24LE,   pcm_u24le);
 PCM_CODEC(CODEC_ID_PCM_U32BE,   pcm_u32be);
 PCM_CODEC(CODEC_ID_PCM_U32LE,   pcm_u32le);
+PCM_CODEC(CODEC_ID_PCM_ZORK,    pcm_zork);
 
 /* ADPCM codecs */
 
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 1fd891caa1..57bffbbda0 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -185,6 +185,7 @@ enum CodecID {
     CODEC_ID_PCM_U24LE,
     CODEC_ID_PCM_U24BE,
     CODEC_ID_PCM_S24DAUD,
+    CODEC_ID_PCM_ZORK,
 
     /* various ADPCM codecs */
     CODEC_ID_ADPCM_IMA_QT= 0x11000,
diff --git a/libavcodec/pcm.c b/libavcodec/pcm.c
index 2551d12b65..c0383adabc 100644
--- a/libavcodec/pcm.c
+++ b/libavcodec/pcm.c
@@ -291,6 +291,14 @@ static int pcm_encode_frame(AVCodecContext *avctx,
             *dst++ = (v >> 8) + 128;
         }
         break;
+    case CODEC_ID_PCM_ZORK:
+        for(;n>0;n--) {
+            v= *samples++ >> 8;
+            if(v<0)   v = -v;
+            else      v+= 128;
+            *dst++ = v;
+        }
+        break;
     case CODEC_ID_PCM_ALAW:
         for(;n>0;n--) {
             v = *samples++;
@@ -452,6 +460,15 @@ static int pcm_decode_frame(AVCodecContext *avctx,
             *samples++ = ((int)*src++ - 128) << 8;
         }
         break;
+    case CODEC_ID_PCM_ZORK:
+        n = buf_size;
+        for(;n>0;n--) {
+            int x= *src++;
+            if(x&128) x-= 128;
+            else      x = -x;
+            *samples++ = x << 8;
+        }
+        break;
     case CODEC_ID_PCM_ALAW:
     case CODEC_ID_PCM_MULAW:
         n = buf_size;
@@ -505,5 +522,6 @@ PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
 PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
 PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
 PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);
+PCM_CODEC(CODEC_ID_PCM_ZORK, pcm_zork);
 
 #undef PCM_CODEC
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 0cb9e32419..4ad732daba 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -415,6 +415,8 @@ int wav_codec_get_id(unsigned int tag, int bps)
         id = CODEC_ID_PCM_S24LE;
     if (id == CODEC_ID_PCM_S16LE && bps == 32)
         id = CODEC_ID_PCM_S32LE;
+    if (id == CODEC_ID_ADPCM_IMA_WAV && bps == 8)
+        id = CODEC_ID_PCM_ZORK;
     return id;
 }
 #endif // CONFIG_DEMUXERS
-- 
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