Added Encoder support

codec/Makefile.am

@@ -28,7 +28,8 @@ libalac_la_SOURCES = \
     dp_enc.c \
     matrix_dec.c \
     matrix_enc.c \
-    libalac.cpp
+    libalac_encoder.cpp \
+    libalac_decoder.cpp
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = alac.pc

codec/libalac.h

@@ -19,6 +19,23 @@ int alac_encoder_get_magic_cookie(alac_encoder* encoder, unsigned char * output)
 int alac_encoder_write(alac_encoder* encoder, const unsigned char * input, int input_size, unsigned char * output);
 void alac_encoder_delete(alac_encoder* encoder);
 
+typedef struct {
+    void *ptr;
+    int sample_rate;
+    int channels;
+    int bit_depth;
+    int frames_per_packet;
+    int input_max_packet_size;
+    int output_packet_size;
+
+} alac_decoder;
+
+typedef struct {
+    int input_bytes_used;
+    int output_bytes;
+
+} alac_decoder_read_result;
+
 #ifdef __cplusplus
 }
 #endif

codec/libalac_decoder.cpp

@@ -0,0 +1,70 @@
+#include <vector>
+#include <cstdio>
+#include "libalac.h"
+#include "ALACDecoder.h"
+#include "ALACBitUtilities.h"
+
+enum
+{
+    kTestFormatFlag_16BitSourceData    = 1,
+    kTestFormatFlag_20BitSourceData    = 2,
+    kTestFormatFlag_24BitSourceData    = 3,
+    kTestFormatFlag_32BitSourceData    = 4
+};
+
+alac_decoder alac_decoder_new(const unsigned char* magicCookie, int magicCookieSize) {
+    alac_decoder decoder;
+    decoder.ptr = nullptr;
+
+
+
+    auto d = new ALACDecoder();
+    if(d->Init((void *) magicCookie, magicCookieSize) != ALAC_noErr){
+        delete d;
+        return decoder;
+    }
+
+    decoder.ptr = d;
+    decoder.sample_rate = d->mConfig.sampleRate;
+    decoder.channels = d->mConfig.numChannels;
+    decoder.bit_depth = d->mConfig.bitDepth;
+    decoder.frames_per_packet = d->mConfig.frameLength;
+
+    decoder.input_max_packet_size = decoder.channels * (decoder.bit_depth >> 3) * decoder.frames_per_packet + kALACMaxEscapeHeaderBytes;
+    decoder.output_packet_size = decoder.channels * (decoder.bit_depth >> 3) * decoder.frames_per_packet;
+
+    return decoder;
+}
+
+alac_decoder_read_result alac_decoder_read(alac_decoder* decoder, const unsigned char * input, int input_size, unsigned char * output){
+    if(decoder->ptr == nullptr){
+        return {-1, -1};
+    }
+
+    auto d = reinterpret_cast<ALACDecoder*>(decoder->ptr);
+
+    if(input_size > decoder->input_max_packet_size){
+        return {-1, -1};
+    }
+
+
+
+    BitBuffer inputBuffer;
+    BitBufferInit(&inputBuffer, reinterpret_cast<uint8_t *>(decoder), input_size);
+
+    uint32_t ioNumSamples = input_size;
+    if(d->Decode(&inputBuffer, output, decoder->frames_per_packet, decoder->channels, &ioNumSamples) != ALAC_noErr){
+        return  {-1, -1};
+    }
+
+
+    return  {static_cast<int>(BitBufferGetPosition(&inputBuffer) / 8), static_cast<int>(ioNumSamples * (decoder->bit_depth >> 3))};
+}
+
+void alac_decoder_delete(alac_decoder* decoder){
+    if(decoder->ptr == nullptr){
+        return;
+    }
+    delete reinterpret_cast<ALACDecoder*>(decoder->ptr);
+    decoder->ptr = nullptr;
+}

codec/libalac_encoder.cpp

@@ -150,6 +150,9 @@ int alac_encoder_write(alac_encoder* encoder, const unsigned char * input, int i
 }
 
 void alac_encoder_delete(alac_encoder* encoder){
+    if(encoder->ptr == nullptr){
+        return;
+    }
     delete reinterpret_cast<ALACEncoder*>(encoder->ptr);
     encoder->ptr = nullptr;
 }