first pass at ALAC decoder from David Hammerton; while David's original

decoder works great, this decoder is not completely and seamlessly
integrated yet with FFmpeg


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@4008 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

CREDITS

@@ -14,6 +14,7 @@ Brian Foley
 Arpad Gereoffy
 Philip Gladstone
 Vladimir Gneushev
+David Hammerton
 Wolfgang Hesseler
 Falk Hueffner
 Zdenek Kabelac

libavcodec/Makefile

 #
 # libavcodec Makefile
-# (c) 2000-2003 Fabrice Bellard
+# (c) 2000-2005 Fabrice Bellard
 #
 include ../config.mak
 
@@ -22,7 +22,8 @@ OBJS= bitstream.o utils.o mem.o allcodecs.o \
       smc.o parser.o flicvideo.o truemotion1.o vmdav.o lcl.o qtrle.o g726.o \
       flac.o vp3dsp.o integer.o snow.o tscc.o sonic.o ulti.o h264idct.o \
       qdrw.o xl.o rangecoder.o png.o pnm.o qpeg.o vc9.o h263.o h261.o \
-      msmpeg4.o h263dec.o svq1.o rv10.o wmadec.o indeo3.o shorten.o loco.o
+      msmpeg4.o h263dec.o svq1.o rv10.o wmadec.o indeo3.o shorten.o loco.o \
+      alac.o
 
 AMROBJS=
 ifeq ($(AMR_NB),yes)

libavcodec/allcodecs.c

@@ -196,6 +196,7 @@ void avcodec_register_all(void)
     register_avcodec(&qtrle_decoder);
     register_avcodec(&flac_decoder);
     register_avcodec(&shorten_decoder);
+    register_avcodec(&alac_decoder);
 #endif /* CONFIG_DECODERS */
 
 #ifdef AMR_NB

libavcodec/avcodec.h

@@ -17,7 +17,7 @@ extern "C" {
 
 #define FFMPEG_VERSION_INT     0x000409
 #define FFMPEG_VERSION         "0.4.9-pre1"
-#define LIBAVCODEC_BUILD       4744
+#define LIBAVCODEC_BUILD       4745
 
 #define LIBAVCODEC_VERSION_INT FFMPEG_VERSION_INT
 #define LIBAVCODEC_VERSION     FFMPEG_VERSION
@@ -170,6 +170,7 @@ enum CodecID {
     
     CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport
                          stream (only used by libavformat) */
+    CODEC_ID_ALAC,
 };
 
 /* CODEC_ID_MP3LAME is absolete */
@@ -2011,6 +2012,7 @@ extern AVCodec xl_decoder;
 extern AVCodec qpeg_decoder;
 extern AVCodec shorten_decoder;
 extern AVCodec loco_decoder;
+extern AVCodec alac_decoder;
 
 /* pcm codecs */
 #define PCM_CODEC(id, name) \

libavformat/mov.c

@@ -142,6 +142,7 @@ static const CodecTag mov_audio_tags[] = {
     { CODEC_ID_AMR_NB, MKTAG('s', 'a', 'm', 'r') }, /* AMR-NB 3gp */
     { CODEC_ID_AMR_WB, MKTAG('s', 'a', 'w', 'b') }, /* AMR-WB 3gp */
     { CODEC_ID_AC3, MKTAG('m', 's', 0x20, 0x00) }, /* Dolby AC-3 */
+    { CODEC_ID_ALAC,MKTAG('a', 'l', 'a', 'c') }, /* Apple Lossless */
     { CODEC_ID_NONE, 0 },
 };
 
@@ -1101,6 +1102,23 @@ static int mov_read_stsd(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
                    st->codec.channels = (px[1] >> 3) & 15;
                 }
             }
+            else if( st->codec.codec_tag == MKTAG( 'a', 'l', 'a', 'c' ))
+            {
+                /* Handle alac audio tag + special extradata */
+                get_be32(pb); /* version */
+                get_be32(pb);
+                st->codec.channels = get_be16(pb); /* channels */
+                st->codec.bits_per_sample = get_be16(pb); /* bits per sample */
+                get_be32(pb);
+                st->codec.sample_rate = get_be16(pb);
+                get_be16(pb);
+
+                /* fetch the 36-byte extradata needed for alac decoding */
+                st->codec.extradata_size = 36;
+                st->codec.extradata = (uint8_t*) 
+                    av_mallocz(st->codec.extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
+                get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
+            }
 	    else if(size>=(16+20))
 	    {//16 bytes read, reading atleast 20 more
                 uint16_t version;