代码之家 › 专栏 › 技术社区 › Era

AVAssetReader不读取整个文件?

avfoundation ios cocoa-touch objective-c

Era · 技术社区 · 15 年前

我正在用AVAssetReader和AVAssetReaderTrackOutput从iOS上的iPod库读取音频资源。但是,当我读取数据并将块放回一起时,文件并不完全相同。缺少几kB,因此音频文件无法播放。

// Copy next audio samples
CMSampleBufferRef buffer = [[reader_.outputs objectAtIndex:0] copyNextSampleBuffer];

// Extract bytes from buffer
CMBlockBufferRef dataBuffer = CMSampleBufferGetDataBuffer(buffer);

size_t bufLen = CMBlockBufferGetDataLength(dataBuffer);
UInt8 buf[bufLen];

CMBlockBufferCopyDataBytes(dataBuffer, 0, bufLen, buf);

// Pass data to delegate
if ([delegate respondsToSelector:@selector(assetStream:hasDataAvailable:)]) {
    [delegate assetStream:self hasDataAvailable:[NSData dataWithBytes:buf length:bufLen]];
}

// Invalidate buffer
CMSampleBufferInvalidate(buffer);

我在这里做错什么了?