如何将CMSampleBufferRef转换为NSData [英] How to convert CMSampleBufferRef to NSData

问题描述

如何将CMSampleBufferRef转换为NSData？

How do you convert CMSampleBufferRef to NSData?

我设法获取 MPMediaItem 的数据按照Erik Aigner关于此主题的回答，但数据类型为 CMSampleBufferRef 。

I've managed to get the data for an MPMediaItem by following Erik Aigner's answer on this thread, however the data is of type CMSampleBufferRef.

我知道CMSampleBufferRef是一个结构，在 CMSampleBuffer参考，但我不认为我完全理解它是什么。没有一个CMSampleBuffer函数似乎是一个明显的解决方案。

I know CMSampleBufferRef is a struct and is defined in the CMSampleBuffer Reference in the iOS Dev Library, but I don't think I fully understand what it is. None of the CMSampleBuffer functions seem to be an obvious solution.

推荐答案

这里你去了音频样本缓冲区，这是你的正在查看，如果您想查看整个过程（将所有音频数据从MPMediaItem获取到文件中，请查看 this 问题

Here you go this works for audio sample buffer which is what you are looking at, and if you want to look at the whole process (getting all audio data from MPMediaItem into a file check out this question

CMSampleBufferRef ref=[output copyNextSampleBuffer];
        // NSLog(@"%@",ref);
        if(ref==NULL)
            break;
        //copy data to file
        //read next one
        AudioBufferList audioBufferList;
        NSMutableData *data=[[NSMutableData alloc] init];
        CMBlockBufferRef blockBuffer;
        CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(ref, NULL, &audioBufferList, sizeof(audioBufferList), NULL, NULL, 0, &blockBuffer);
        // NSLog(@"%@",blockBuffer);



        for( int y=0; y<audioBufferList.mNumberBuffers; y++ )
        {
            AudioBuffer audioBuffer = audioBufferList.mBuffers[y];
            Float32 *frame = (Float32*)audioBuffer.mData;


            [data appendBytes:frame length:audioBuffer.mDataByteSize];



        }


        CFRelease(blockBuffer);
        CFRelease(ref);
        ref=NULL;
        blockBuffer=NULL;
        [data release];

这篇关于如何将CMSampleBufferRef转换为NSData的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！