OggData.cpp

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//
// C++ implementation: Audio::__impl::OggData
//

#include "config.h"

#ifdef HAVE_OGG
#include <sys/types.h>
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#include "OggData.h"
#include "config.h"
#include "../Format.h"
#include "../Exceptions.h"

#include <utility>
#include <limits>

#include <vorbis/vorbisfile.h>
#include "vsfilesystem.h"


namespace Audio {

    namespace __impl {
    
        using std::numeric_limits;
    
        size_t OggData::read_func(void *ptr, size_t size, size_t nmemb, void *datasource)
        {
            return ((VSFileSystem::VSFile*)datasource)->Read(ptr, size*nmemb);
        }
        
        int OggData::seek_func(void *datasource, ogg_int64_t offset, int whence)
        {
            if (offset > numeric_limits<long>::max())
                return -1;
            
            VSFileSystem::VSFile *file = (VSFileSystem::VSFile*)datasource;
            switch(whence) {
            case SEEK_SET:
                file->GoTo((long)offset);
                break;
            case SEEK_END:
                file->GoTo(file->Size() + (long)offset);
                break;
            case SEEK_CUR:
                file->GoTo(file->GetPosition() + (long)offset);
                break;
            default:
                return -1;
            }
            
            return 0;
        }
        
        int OggData::close_func(void *datasource)
        {
            ((VSFileSystem::VSFile*)datasource)->Close();
            return 0;
        }
        
        long OggData::tell_func(void *datasource)
        {
            return ((VSFileSystem::VSFile*)datasource)->GetPosition();
        }
        
        int OggData::nativeIsLsb()
        {
            union {
                short s;
                char c[sizeof(short)];
            };
            s = 1;
            return c[0]?1:0;
        }
        
        OggData::OggData(VSFileSystem::VSFile &file, Format &fmt, int streamIdx, bool test) 
        {
            callbacks.read_func = &read_func;
            callbacks.seek_func = &seek_func;
            callbacks.close_func = &close_func;
            callbacks.tell_func = &tell_func;
            
            streamIndex = streamIdx;
            
            if (test) {
                if (ov_test_callbacks(&file, &vorbisFile, NULL, 0, callbacks))
                    throw FileFormatException("File \"" + file.GetFilename() + "\"is not ogg vorbis");
            } else {
                if (ov_open_callbacks(&file, &vorbisFile, NULL, 0, callbacks))
                    throw FileFormatException("File \"" + file.GetFilename() + "\"is not ogg vorbis");
            
                vorbis_info *info = ov_info(&vorbisFile, streamIndex);
                fmt.sampleFrequency = info->rate;
                fmt.channels = info->channels;
                fmt.bitsPerSample = 16;
                fmt.nativeOrder = nativeIsLsb();
                fmt.signedSamples = 1;
            }
        }
        
        OggData::~OggData()
        {
            ov_clear(&vorbisFile);
        }
    }

};

#endif // HAVE_OGG