视频颜色空间NV12 转RGB

使用ijkplayer开源框架做视频播放器渲染画面的时候需要用到RGB格式的颜色，但是解码出来的视频帧默认为NV12的格式，所以需要做一下格式转换。

NSMutableArray* _overlayDatas;

structSwsContext*nv12_420_ctx;

structSwsContext*rgb_420_ctx;

AVFrame*nv12_420_frame;

AVFrame* rgb_420_frame;

- (void)setupScaler:(SDL_VoutOverlay*) overlay

{

//初始化nv12 转 420p

nv12_420_frame = av_frame_alloc();

int res = av_image_alloc(nv12_420_frame->data, nv12_420_frame->linesize, overlay->w, overlay->h, AV_PIX_FMT_YUV420P, 1);

if(res <0) {

NSLog(@"失败");

}

// avpicture_alloc(&nv12_420_frame, AV_PIX_FMT_YUV420P, overlay->w, overlay->h);

staticintsws_flags = SWS_FAST_BILINEAR;

nv12_420_ctx = sws_getContext(overlay->w,

   overlay->h,

   AV_PIX_FMT_NV12,

   overlay->w,

   overlay->h,

   AV_PIX_FMT_YUV420P,

   sws_flags,NULL,NULL,NULL);

//初始化420p 转 rgb24

rgb_420_frame = av_frame_alloc();

int res1 = av_image_alloc(rgb_420_frame->data, rgb_420_frame->linesize, overlay->w, overlay->h, AV_PIX_FMT_RGB24, 1);

if(res1 <0) {

NSLog(@"失败");

}

// avpicture_alloc(&rgb_420_frame, AV_PIX_FMT_RGB24, overlay->w, overlay->h);

// return;

rgb_420_ctx = sws_getContext(overlay->w,

   overlay->h,

   AV_PIX_FMT_YUV420P,

   overlay->w,

   overlay->h,

   AV_PIX_FMT_RGB24,

   sws_flags,NULL,NULL,NULL);

}

- (void)convertFrameToRGB:(SDL_VoutOverlay*) overlay

{

intlinesize[3] = { overlay->pitches[0], overlay->pitches[1], overlay->pitches[2] };

sws_scale(nv12_420_ctx,

(constuint8_t**)overlay->pixels,

linesize,

0,

overlay->h,

nv12_420_frame->data,

nv12_420_frame->linesize);

// return;

sws_scale(rgb_420_ctx,

(constuint8_t**)nv12_420_frame->data,

nv12_420_frame->linesize,

0,

overlay->h,

rgb_420_frame->data,

rgb_420_frame->linesize);

}

- (GLuint) curTexture

{

if(_overlayDatas.count>0) {

NSValue* pixelValue = [_overlayDatasobjectAtIndex:0];

[_overlayDatas removeObjectAtIndex:0];

SDL_VoutOverlay* overlay = (SDL_VoutOverlay*)[pixelValuepointerValue];

if(!nv12_420_ctx) {

[selfsetupScaler:overlay];

}

[selfconvertFrameToRGB:overlay];

GLuinttexture =0;

glGenTextures(1, &texture);

glBindTexture(GL_TEXTURE_2D, texture);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

glTexImage2D(GL_TEXTURE_2D,0,GL_RGB, overlay->w, overlay->h,0,GL_RGB,GL_UNSIGNED_BYTE, overlay->pixels[0]);

GLenumglError =glGetError();

if(GL_NO_ERROR!= glError) {

NSLog(@"glError %x\n", glError);

}

returntexture;

}

return 0;

}

- (void)releaseAVFrame {

NSLog(@"111111111111releaseAVFrame");

// av_frame_free(&nv12_420_frame);

sws_freeContext(nv12_420_ctx);

avpicture_free(&nv12_420_frame);

// av_frame_free(&rgb_420_frame);

avpicture_free(&rgb_420_frame);

sws_freeContext(rgb_420_ctx);

[_overlayDatas removeAllObjects];

_overlayDatas = nil;

}

- (void)display: (SDL_VoutOverlay*) overlay

{

dispatch_sync(dispatch_get_main_queue(), ^{

// 省略原来的代码

if(overlay !=NULL&& _overlayDatas.count<1) {

NSValue* overlayValue = [NSValuevalueWithPointer:overlay];

[_overlayDatasaddObject:overlayValue];

}

[self unlockGLActive];

});

}