// // MusepackFile.m // zyVorbis // // Created by Vincent Spader on 1/23/05. // Copyright 2005 Vincent Spader All rights reserved. // #import "MusepackDecoder.h" @implementation MusepackDecoder mpc_int32_t ReadProc(void *data, void *ptr, mpc_int32_t size) { MusepackDecoder *decoder = (MusepackDecoder *) data; return [[decoder source] read:ptr amount:size]; } mpc_bool_t SeekProc(void *data, mpc_int32_t offset) { MusepackDecoder *decoder = (MusepackDecoder *) data; return [[decoder source] seek:offset whence:SEEK_SET]; } mpc_int32_t TellProc(void *data) { MusepackDecoder *decoder = (MusepackDecoder *) data; return [[decoder source] tell]; } mpc_int32_t GetSizeProc(void *data) { MusepackDecoder *decoder = (MusepackDecoder *) data; if ([[decoder source] seekable]) { long currentPos = [[decoder source] tell]; [[decoder source] seek:0 whence:SEEK_END]; long size = [[decoder source] tell]; [[decoder source] seek:currentPos whence:SEEK_SET]; return size; } else { return 0; } } mpc_bool_t CanSeekProc(void *data) { MusepackDecoder *decoder = (MusepackDecoder *) data; return [[decoder source] seekable]; } - (BOOL)open:(id)s { [self setSource: s]; reader.read = ReadProc; reader.seek = SeekProc; reader.tell = TellProc; reader.get_size = GetSizeProc; reader.canseek = CanSeekProc; reader.data = self; mpc_streaminfo_init(&info); if (mpc_streaminfo_read(&info, &reader) != ERROR_CODE_OK) { NSLog(@"Not a valid musepack file."); return NO; } /* instantiate a decoder with our reader */ mpc_decoder_setup(&decoder, &reader); if (!mpc_decoder_initialize(&decoder, &info)) { NSLog(@"Error initializing decoder."); return NO; } bitrate = (int)(info.average_bitrate/1000.0); frequency = info.sample_freq; totalFrames = mpc_streaminfo_get_length_samples(&info); [self willChangeValueForKey:@"properties"]; [self didChangeValueForKey:@"properties"]; return YES; } - (BOOL)writeToBuffer:(uint16_t *)sample_buffer fromBuffer:(const MPC_SAMPLE_FORMAT *)p_buffer frames:(unsigned)frames { unsigned n; int m_bps = 16; int clip_min = - 1 << (m_bps - 1), clip_max = (1 << (m_bps - 1)) - 1, float_scale = 1 << (m_bps - 1); unsigned p_size = frames * 2; //2 = bits per sample for (n = 0; n < p_size; n++) { int val; #ifdef MPC_FIXED_POINT val = shift_signed( p_buffer[n], m_bps - MPC_FIXED_POINT_SCALE_SHIFT ); #else val = (int)( p_buffer[n] * float_scale ); #endif if (val < clip_min) val = clip_min; else if (val > clip_max) val = clip_max; // sample_buffer[n] = CFSwapInt16LittleToHost(val); sample_buffer[n] = val; } // m_data_bytes_written += p_size * (m_bps >> 3); return YES; } - (int)readAudio:(void *)buf frames:(UInt32)frames { MPC_SAMPLE_FORMAT sampleBuffer[MPC_DECODER_BUFFER_LENGTH]; int framesRead = 0; int bytesPerFrame = 4; //bitsPerSample == 16, channels == 2 while (framesRead < frames) { //Fill from buffer, going by bufferFrames //if still needs more, decode and repeat if (bufferFrames == 0) { /* returns the length of the samples*/ unsigned status = mpc_decoder_decode(&decoder, sampleBuffer, 0, 0); if (status == (unsigned)( -1)) { //decode error NSLog(@"Decode error"); return 0; } else if (status == 0) //EOF { return 0; } else //status>0 /* status == MPC_FRAME_LENGTH */ { } bufferFrames = status; } int framesToRead = bufferFrames; if (bufferFrames > frames) { framesToRead = frames; } [self writeToBuffer:((uint16_t*)(buf + (framesRead*bytesPerFrame))) fromBuffer:sampleBuffer frames: bufferFrames]; frames -= framesToRead; framesRead += framesToRead; bufferFrames -= framesToRead; if (bufferFrames > 0) { memmove((uint8_t *)sampleBuffer, ((uint8_t *)sampleBuffer) + (framesToRead * bytesPerFrame), bufferFrames * bytesPerFrame); } } return framesRead; } - (void)close { [source close]; } - (long)seek:(long)sample { mpc_decoder_seek_sample(&decoder, sample); return sample; } - (void)setSource:(id)s { [s retain]; [source release]; source = s; } - (id)source { return source; } - (NSDictionary *)properties { return [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:bitrate], @"bitrate", [NSNumber numberWithFloat:frequency], @"sampleRate", [NSNumber numberWithDouble:totalFrames], @"totalFrames", [NSNumber numberWithInt:16], @"bitsPerSample", [NSNumber numberWithInt:2], @"channels", [NSNumber numberWithBool:[source seekable]], @"seekable", @"host",@"endian", nil]; } + (NSArray *)fileTypes { return [NSArray arrayWithObject:@"mpc"]; } + (NSArray *)mimeTypes { return [NSArray arrayWithObjects:@"audio/x-musepack", nil]; } @end