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网易云信播放器 Flutter 封装
事情是这样的 我们公司的业务是有 视频播放这一块业务 而且 是基于网易云信的 视频服务的 做的开发 。公司的App开发框架是使用 Flutter , 那么问题来了 Flutter 怎么 实现视频播放嘞 , 官方给出的解决方案 是 ### video_player 这个库的 实现 是 原生端做视频解码 然后通过 Texture 的方式 映射到 Flutter 中 但是解码器 IOS 使用的是 官方的 AVPlayer(苹果官方提供的播放器 啥都好 就是不支持流媒体播放 ) Android 解码器则是 exoplayer 很好很nice
但是
网易云信的视频 是加密的 只有自己的 播放器sdk 在能解码播放 android 和 ios 都支持流媒体 so 只能自己封装
Android 使用 SurfaceTexture 衔接 视频流 正常 但是 ios emmm 网易云信 播放器 返回 的 编码格式 是 NELP_YUV420 就是 YUV420 直接映射到 Flutter 黑屏 但是有声音
//获取 视频回调 数据
[_player registerGetVideoRawDataCB:NELP_YUV420 and:^(NELPVideoRawData *frame) {
Videodata=frame;
}];
因为Skia 引擎底层只支持了 BGRA 格式的视频数据 所以 和黑屏了
首先我们吧 YUV420 转换成 CVPixelBufferRef 方法如下
该方法依赖 libyuv 请自行导入
+ (CVPixelBufferRef)i420FrameToPixelBuffer:(NSData *)i420Frame width:( int )frameWidth height:( int )frameHeight
{
int width = frameWidth;
int height = frameHeight;
*if (i420Frame == nil) {
return NULL;
}
CVPixelBufferRef pixelBuffer = NULL ;
NSDictionary *pixelBufferAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
[NSDictionary dictionary], ( id )kCVPixelBufferIOSurfacePropertiesKey,
nil ];
CVReturn result = CVPixelBufferCreate(kCFAllocatorDefault,
width,
height,
kCVPixelFormatType_420YpCbCr8BiPlanarFullRange,
( __bridge CFDictionaryRef)pixelBufferAttributes,
&pixelBuffer);
if (result != kCVReturnSuccess) {
NSLog(@"Failed to create pixel buffer: %d", result);
return NULL ;
}
result = CVPixelBufferLockBaseAddress(pixelBuffer, 0);
if (result != kCVReturnSuccess) {
CFRelease(pixelBuffer);
NSLog(@"Failed to lock base address: %d", result);
return NULL ;
}
uint8 *dstY = (uint8 *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
int dstStrideY = (**int**)CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
uint8* dstUV = (uint8*)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
int dstStrideUV = ( int )CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1);
UInt8 *_planeData[3];
NSUInteger _stride[3];
CFDataRef dataref = ( __bridge CFDataRef)i420Frame;
uint8 * _data = (UInt8 *) CFDataGetBytePtr(dataref);
_planeData[NEI420FramePlaneY] = _data;
_planeData[NEI420FramePlaneU] = _planeData[NEI420FramePlaneY] + width * height;
_planeData[NEI420FramePlaneV] = _planeData[NEI420FramePlaneU] + width * height / 4;
_stride[NEI420FramePlaneY] = width;
_stride[NEI420FramePlaneU] = width >> 1;
_stride[NEI420FramePlaneV] = width >> 1;
#ifndef KLSMediaCaptureDemoCondense
int ret = libyuv::I420ToNV12(_planeData[NEI420FramePlaneY], ( int )_stride[NEI420FramePlaneY],
_planeData[NEI420FramePlaneU], ( int )_stride[NEI420FramePlaneU],
_planeData[NEI420FramePlaneV], ( int )_stride[NEI420FramePlaneV],
dstY, dstStrideY,
dstUV, dstStrideUV,
width, height);
#endif
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
#ifndef KLSMediaCaptureDemoCondense
if (ret) {
NSLog(@"Error converting I420 VideoFrame to NV12: %d", result);
CFRelease(pixelBuffer);
return NULL ;
}
#endif
return pixelBuffer;
}
然后是 pixelBuffer To SampleBuffer
+ (CMSampleBufferRef)pixelBufferToSampleBuffer:(CVPixelBufferRef)pixelBuffer
{
CMSampleBufferRef sampleBuffer;
CMTime frameTime = CMTimeMakeWithSeconds([[NSDate date] timeIntervalSince1970], 1000000000);
CMSampleTimingInfo timing = {frameTime, frameTime, kCMTimeInvalid};
CMVideoFormatDescriptionRef videoInfo = NULL ;
CMVideoFormatDescriptionCreateForImageBuffer( NULL , pixelBuffer, &videoInfo);
OSStatus status = CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, true , NULL , NULL , videoInfo, &timing, &sampleBuffer);
if (status != noErr) {
NSLog(@"Failed to create sample buffer with error %d.", ( int )status);
}
CVPixelBufferRelease(pixelBuffer);
if (videoInfo)
CFRelease(videoInfo);
return sampleBuffer;
}
最后吧 SmapleBuffer 转换 BGRA
_//转化_
-(CVPixelBufferRef)convertVideoSmapleBufferToBGRAData:(CMSampleBufferRef)videoSample{
_//CVPixelBufferRef是CVImageBufferRef的别名，两者操作几乎一致。_
_//获取CMSampleBuffer的图像地址_
CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(videoSample);
_//VideoToolbox解码后的图像数据并不能直接给CPU访问，需先用CVPixelBufferLockBaseAddress()锁定地址才能从主存访问，否则调用CVPixelBufferGetBaseAddressOfPlane等函数则返回NULL或无效值。值得注意的是，CVPixelBufferLockBaseAddress自身的调用并不消耗多少性能，一般情况，锁定之后，往CVPixelBuffer拷贝内存才是相对耗时的操作，比如计算内存偏移。_
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
_//图像宽度（像素）_
size_t pixelWidth = CVPixelBufferGetWidth(pixelBuffer);
_//图像高度（像素）_
size_t pixelHeight = CVPixelBufferGetHeight(pixelBuffer);
_//获取CVImageBufferRef中的y数据_
uint8_t *y_frame = ( unsigned char *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
_//获取CMVImageBufferRef中的uv数据_
uint8_t *uv_frame =( unsigned char *) CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
_// 创建一个空的32BGRA格式的CVPixelBufferRef_
NSDictionary *pixelAttributes = @{( id )kCVPixelBufferIOSurfacePropertiesKey : @{}};
CVPixelBufferRef pixelBuffer1 = NULL ;
CVReturn result = CVPixelBufferCreate(kCFAllocatorDefault,
pixelWidth,pixelHeight,kCVPixelFormatType_32BGRA,
( __bridge CFDictionaryRef)pixelAttributes,&pixelBuffer1);
if (result != kCVReturnSuccess) {
NSLog(@"Unable to create cvpixelbuffer %d", result);
return NULL ;
}
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
result = CVPixelBufferLockBaseAddress(pixelBuffer1, 0);
if (result != kCVReturnSuccess) {
CFRelease(pixelBuffer1);
NSLog(@"Failed to lock base address: %d", result);
return NULL ;
}
_// 得到新创建的CVPixelBufferRef中 rgb数据的首地址_
uint8_t *rgb_data = (uint8*)CVPixelBufferGetBaseAddress(pixelBuffer1);
_// 使用libyuv为rgb_data写入数据，将NV12转换为BGRA_
int ret = NV12ToARGB(y_frame, pixelWidth, uv_frame, pixelWidth, rgb_data, pixelWidth * 4, pixelWidth, pixelHeight);
if (ret) {
NSLog(@"Error converting NV12 VideoFrame to BGRA: %d", result);
CFRelease(pixelBuffer1);
return NULL ;
}
CVPixelBufferUnlockBaseAddress(pixelBuffer1, 0);
return pixelBuffer1;
}
方法如何使用
if(Videodata){
int width,height;
width=Videodata->width;
height=Videodata->height;
int len = Videodata->width * Videodata->height * 3 / 2;
NSData * data = [[NSData alloc] initWithBytes:Videodata->UsrData length:len];
CVPixelBufferRef originalPixelBuffer = [NEYUVConverter i420FrameToPixelBuffer:data width:Videodata->width height:Videodata->height];
CMSampleBufferRef sampleBuffer = [NEYUVConverter pixelBufferToSampleBuffer:originalPixelBuffer];
CVPixelBufferRef finalPiexelBuffer;
finalPiexelBuffer = [ self convertVideoSmapleBufferToBGRAData:sampleBuffer];
CVPixelBufferRelease(originalPixelBuffer);
return finalPiexelBuffer;
}
转载：姜姜和张张
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