Add C libalac interface for encoder

README.md

@@ -21,7 +21,7 @@ To download, build and install `libalac` do the following:
 
 * Clone the repository and `cd` into the folder:
 ```
-$ git clone https://github.com/mikebrady/alac.git
+$ git clone https://git.gammaspectra.live/S.O.N.G/alac.git
 $ cd alac
 ```
 * Configure the build and make the library:

codec/Makefile.am

@@ -27,7 +27,8 @@ libalac_la_SOURCES = \
     dp_dec.c \
     dp_enc.c \
     matrix_dec.c \
-    matrix_enc.c
+    matrix_enc.c \
+    libalac.cpp
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = alac.pc

codec/libalac.cpp

@@ -0,0 +1,134 @@
+#include <vector>
+#include "libalac.h"
+#include "ALACEncoder.h"
+#include "ALACBitUtilities.h"
+
+enum
+{
+    kTestFormatFlag_16BitSourceData    = 1,
+    kTestFormatFlag_20BitSourceData    = 2,
+    kTestFormatFlag_24BitSourceData    = 3,
+    kTestFormatFlag_32BitSourceData    = 4
+};
+
+alac_encoder alac_encoder_new(int sampleRate, int channels, int bitDepth, int fastMode) {
+    alac_encoder encoder;
+    encoder.ptr = nullptr;
+    encoder.sample_rate = sampleRate;
+    encoder.channels = channels;
+    encoder.bit_depth = bitDepth;
+    encoder.input_packet_size = 0;
+    encoder.output_max_packet_size = 0;
+
+    AudioFormatDescription d;
+    d.mFormatID = kALACFormatAppleLossless;
+    d.mSampleRate = static_cast<alac_float64_t>(sampleRate);
+
+    switch (bitDepth) {
+        //TODO: hmm, source bit data?
+        case 16:
+            d.mFormatFlags = kTestFormatFlag_16BitSourceData;
+            break;
+        case 20:
+            d.mFormatFlags = kTestFormatFlag_20BitSourceData;
+            break;
+        case 24:
+            d.mFormatFlags = kTestFormatFlag_24BitSourceData;
+            break;
+        case 32:
+            d.mFormatFlags = kTestFormatFlag_32BitSourceData;
+            break;
+        default:
+            return encoder;
+    }
+
+    if (channels > kALACMaxChannels) {
+        return encoder;
+    }
+
+    d.mFramesPerPacket = kALACDefaultFramesPerPacket;
+    d.mChannelsPerFrame = channels;
+    d.mBytesPerPacket = 0;
+    d.mBytesPerFrame = 0;
+    d.mBitsPerChannel = 0;
+    d.mReserved = 0;
+
+    auto e = new ALACEncoder();
+
+    e->SetFrameSize(d.mFramesPerPacket);
+    e->SetFastMode(fastMode != 0);
+    if(e->InitializeEncoder(d) != ALAC_noErr){
+        delete e;
+        return encoder;
+    }
+    
+
+    encoder.ptr = e;
+    encoder.input_packet_size = channels * (bitDepth >> 3) * d.mFramesPerPacket;
+    encoder.output_max_packet_size = encoder.input_packet_size + kALACMaxEscapeHeaderBytes;
+
+    return encoder;
+}
+
+int alac_encoder_write(alac_encoder* encoder, const unsigned char * input, int input_size, unsigned char * output){
+    if(encoder->ptr == nullptr){
+        return -1;
+    }
+
+    auto e = reinterpret_cast<ALACEncoder*>(encoder->ptr);
+
+    AudioFormatDescription outputFormat;
+    outputFormat.mFormatID = kALACFormatAppleLossless;
+    outputFormat.mSampleRate = static_cast<alac_float64_t>(encoder->sample_rate);
+    outputFormat.mFramesPerPacket = kALACDefaultFramesPerPacket;
+    outputFormat.mChannelsPerFrame = encoder->channels;
+    outputFormat.mBytesPerPacket = 0;
+    outputFormat.mBytesPerFrame = 0;
+    outputFormat.mBitsPerChannel = 0;
+    outputFormat.mReserved = 0;
+
+    AudioFormatDescription inputFormat;
+    inputFormat.mFormatID = kALACFormatLinearPCM;
+    inputFormat.mSampleRate = static_cast<alac_float64_t>(encoder->sample_rate);
+    inputFormat.mFramesPerPacket = outputFormat.mFramesPerPacket;
+    inputFormat.mChannelsPerFrame = encoder->channels;
+    inputFormat.mBitsPerChannel = encoder->bit_depth;
+    inputFormat.mBytesPerPacket = inputFormat.mBytesPerFrame = inputFormat.mFramesPerPacket * (inputFormat.mBitsPerChannel >> 3) * inputFormat.mChannelsPerFrame;
+    inputFormat.mFormatFlags = kALACFormatFlagIsSignedInteger | kALACFormatFlagIsPacked; //little endian
+    inputFormat.mReserved = 0;
+
+
+    switch (encoder->bit_depth) {
+        //TODO: hmm, source bit data?
+        case 16:
+            outputFormat.mFormatFlags = kTestFormatFlag_16BitSourceData;
+            break;
+        case 20:
+            outputFormat.mFormatFlags = kTestFormatFlag_20BitSourceData;
+            break;
+        case 24:
+            outputFormat.mFormatFlags = kTestFormatFlag_24BitSourceData;
+            break;
+        case 32:
+            outputFormat.mFormatFlags = kTestFormatFlag_32BitSourceData;
+            break;
+    }
+
+    int32_t ioNumBytes = 0;
+
+    if(input_size > inputFormat.mBytesPerPacket){
+        return -1;
+    }
+
+    ioNumBytes = input_size;
+    if(e->Encode(inputFormat, outputFormat, const_cast<unsigned char *>(input), output, &ioNumBytes) != ALAC_noErr){
+        return -1;
+    }
+
+    return ioNumBytes;
+
+}
+void alac_encoder_delete(alac_encoder* encoder){
+    delete reinterpret_cast<ALACEncoder*>(encoder->ptr);
+    encoder->ptr = nullptr;
+}

codec/libalac.h

@@ -0,0 +1,21 @@
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    void *ptr;
+    int sample_rate;
+    int channels;
+    int bit_depth;
+    int input_packet_size;
+    int output_max_packet_size;
+} alac_encoder;
+
+alac_encoder alac_encoder_new(int sampleRate, int channels, int bitDepth, int fastMode);
+int alac_encoder_write(alac_encoder* encoder, const unsigned char * input, int input_size, unsigned char * output);
+void alac_encoder_delete(alac_encoder* encoder);
+
+#ifdef __cplusplus
+}
+#endif