deepvoice_client/local_plugins/opus/ios/Classes/OpusBridge.m

#import "OpusBridge.h"
#import "opus.h"

// 编码器结构体
typedef struct {
    OpusEncoder *encoder;
    int channels;
    int sampleRate;
    int frameSize;
} OpusEncoderWrapper;

// 解码器结构体
typedef struct {
    OpusDecoder *decoder;
    int channels;
    int sampleRate;
} OpusDecoderWrapper;

@implementation OpusBridge {
    OpusEncoderWrapper *_encoderWrapper;
    OpusDecoderWrapper *_decoderWrapper;
}

#pragma mark - 初始化和销毁

- (instancetype)init {
    self = [super init];
    if (self) {
        _encoderWrapper = NULL;
        _decoderWrapper = NULL;
    }
    return self;
}

- (void)dealloc {
    [self disposeEncoder];
    [self disposeDecoder];
}

#pragma mark - 编码器方法

- (BOOL)createEncoderWithSampleRate:(int)sampleRate
                           channels:(int)channels
                        application:(int)application
                         complexity:(int)complexity
                          frameSize:(int)frameSize {
    // 先释放已有资源
    [self disposeEncoder];
    
    int error = OPUS_OK;
    OpusEncoder *encoder = opus_encoder_create(sampleRate, channels, application, &error);
    
    if (error != OPUS_OK || encoder == NULL) {
        NSLog(@"[OpusBridge] Failed to create encoder: %s", opus_strerror(error));
        return NO;
    }
    
    // 设置编码器参数
    opus_encoder_ctl(encoder, OPUS_SET_COMPLEXITY(complexity));
    
    // 创建封装结构
    _encoderWrapper = malloc(sizeof(OpusEncoderWrapper));
    _encoderWrapper->encoder = encoder;
    _encoderWrapper->channels = channels;
    _encoderWrapper->sampleRate = sampleRate;
    _encoderWrapper->frameSize = frameSize;
    
    NSLog(@"[OpusBridge] Encoder created: sampleRate=%d, channels=%d", sampleRate, channels);
    return YES;
}

- (NSData *)encodePCMData:(NSData *)pcmData {
    if (_encoderWrapper == NULL || _encoderWrapper->encoder == NULL) {
        NSLog(@"[OpusBridge] Encoder not initialized");
        return nil;
    }
    
    // 检查PCM数据大小是否匹配
    int frameSize = _encoderWrapper->frameSize;
    int channels = _encoderWrapper->channels;
    
    // PCM数据大小 = 帧大小 * 声道数 * 每样本字节数(2字节)
    int frameBytes = frameSize * channels * 2;
    
    if (pcmData.length < frameBytes) {
        NSLog(@"[OpusBridge] PCM data too small: %lu bytes (need %d bytes)", 
              (unsigned long)pcmData.length, frameBytes);
        return nil;
    }
    
    // 创建输出缓冲区 - 通常编码后的数据会小于PCM，可以用更小的缓冲区
    // 但这里保守起见，使用相同大小的缓冲区
    const int maxEncodedSize = (int)pcmData.length;
    unsigned char *encodedData = malloc(maxEncodedSize);
    
    // 编码
    int encodedBytes = opus_encode(
        _encoderWrapper->encoder,
        (const opus_int16 *)[pcmData bytes],
        frameSize,
        encodedData,
        maxEncodedSize
    );
    
    if (encodedBytes <= 0) {
        NSLog(@"[OpusBridge] Encoding failed: %s", opus_strerror(encodedBytes));
        free(encodedData);
        return nil;
    }
    
    // 封装为NSData并返回
    NSData *result = [NSData dataWithBytes:encodedData length:encodedBytes];
    free(encodedData);
    
    NSLog(@"[OpusBridge] Encoded %d bytes", encodedBytes);
    return result;
}

- (void)disposeEncoder {
    if (_encoderWrapper) {
        if (_encoderWrapper->encoder) {
            opus_encoder_destroy(_encoderWrapper->encoder);
            _encoderWrapper->encoder = NULL;
        }
        free(_encoderWrapper);
        _encoderWrapper = NULL;
        NSLog(@"[OpusBridge] Encoder disposed");
    }
}

#pragma mark - 解码器方法

- (BOOL)createDecoderWithSampleRate:(int)sampleRate channels:(int)channels {
    // 先释放已有资源
    [self disposeDecoder];
    
    int error = OPUS_OK;
    OpusDecoder *decoder = opus_decoder_create(sampleRate, channels, &error);
    
    if (error != OPUS_OK || decoder == NULL) {
        NSLog(@"[OpusBridge] Failed to create decoder: %s", opus_strerror(error));
        return NO;
    }
    
    // 创建封装结构
    _decoderWrapper = malloc(sizeof(OpusDecoderWrapper));
    _decoderWrapper->decoder = decoder;
    _decoderWrapper->channels = channels;
    _decoderWrapper->sampleRate = sampleRate;
    
    NSLog(@"[OpusBridge] Decoder created: sampleRate=%d, channels=%d", sampleRate, channels);
    return YES;
}

- (NSData *)decodeOpusData:(NSData *)opusData frameSize:(int)frameSize {
    if (_decoderWrapper == NULL || _decoderWrapper->decoder == NULL) {
        NSLog(@"[OpusBridge] Decoder not initialized");
        return nil;
    }
    
    // 准备输出缓冲区，frameSize * channels 个short类型
    int outputSizeInSamples = frameSize * _decoderWrapper->channels;
    int outputSizeInBytes = outputSizeInSamples * sizeof(opus_int16);
    
    opus_int16 *outputBuffer = malloc(outputSizeInBytes);
    
    // 解码
    int samplesPerChannel = opus_decode(
        _decoderWrapper->decoder,
        [opusData bytes],
        (int)[opusData length],
        outputBuffer,
        frameSize,
        0 // 不使用FEC
    );
    
    if (samplesPerChannel <= 0) {
        NSLog(@"[OpusBridge] Decoding failed: %s", opus_strerror(samplesPerChannel));
        free(outputBuffer);
        return nil;
    }
    
    // 实际输出大小
    int actualSamples = samplesPerChannel * _decoderWrapper->channels;
    int actualBytes = actualSamples * sizeof(opus_int16);
    
    // 封装为NSData并返回
    NSData *result = [NSData dataWithBytes:outputBuffer length:actualBytes];
    free(outputBuffer);
    
    NSLog(@"[OpusBridge] Decoded %d samples per channel", samplesPerChannel);
    return result;
}

- (void)disposeDecoder {
    if (_decoderWrapper) {
        if (_decoderWrapper->decoder) {
            opus_decoder_destroy(_decoderWrapper->decoder);
            _decoderWrapper->decoder = NULL;
        }
        free(_decoderWrapper);
        _decoderWrapper = NULL;
        NSLog(@"[OpusBridge] Decoder disposed");
    }
}

@end