avcodec YUV到RGB [英] avcodec YUV to RGB

问题描述

我试图使用libswscale将YUV帧转换为RGB。

这是我的代码：

  AVFrame * RGBFrame; 
 SwsContext * ConversionContext; 
 
 ConversionContext = sws_getCachedContext（NULL，FrameWidth，FrameHeight，AV_PIX_FMT_YUV420P，FrameWidth，FrameHeight，AV_PIX_FMT_RGB24，SWS_BILINEAR，0，0，0）; 
 RGBFrame = av_frame_alloc（）; 
 
 avpicture_fill（（AVPicture *）RGBFrame，& FillVect [0]，AV_PIX_FMT_RGB24，FrameWidth，FrameHeight）; 
 
 sws_scale（ConversionContext，VideoFrame-> data，VideoFrame-> linesize，0，VideoFrame-> height，RGBFrame-> data，RGBFrame-> linesize） 
  

我的程序在sws_scale函数中执行SEGFAULT。

VideoFrame是一个保存我解码的帧的AVFrame结构。

我认为这是因为YUV帧来自avcodec_decode_video2，返回一个像这样的数组： p>

  VideoFrame-> data [0] // Y array，linesize = frame width 
 VideoFrame-> data [1] ] // U array，linesize = frame width / 2 
 VideoFrame-> data [2] // V array，linesize = frame width / 2 
  所以，我不知道如何继续转换我的数组，其中Y，U，V数据分为RGB24，使用swscale。
 
 
 
请帮助me，thanks：）
解决方案
  av_frame_alloc 只为框架分配内存对象本身，它不分配存储器来存储图像数据。您已完成：
 
 
 
  FillVect.resize（avpicture_get_size（PIX_FMT_RGB24，FrameWidth，FrameHeight））;  
在调用 avpicture_fill 之前，您的代码中的某处有
 
 
？或者一些其他方法来确保FillVect分配足够的内存来保存整个解码图片？
 
 
 
你尝试在valgrind下运行它，看看SEGFAULT是什么？ p> 
I'm trying to convert an YUV frame to RGB using libswscale.

Here is my code :
AVFrame *RGBFrame;
SwsContext *ConversionContext;

ConversionContext = sws_getCachedContext(NULL, FrameWidth, FrameHeight, AV_PIX_FMT_YUV420P, FrameWidth, FrameHeight, AV_PIX_FMT_RGB24, SWS_BILINEAR, 0, 0, 0);
RGBFrame = av_frame_alloc();

avpicture_fill((AVPicture *)RGBFrame, &FillVect[0], AV_PIX_FMT_RGB24, FrameWidth, FrameHeight);

sws_scale(ConversionContext, VideoFrame->data, VideoFrame->linesize, 0, VideoFrame->height, RGBFrame->data, RGBFrame->linesize);
My program do SEGFAULT on the sws_scale function.

VideoFrame is an AVFrame struct who hold my decoded frame.

I think this is because the YUV frame come from avcodec_decode_video2, which return an array like this :
VideoFrame->data[0] // Y array, linesize = frame width
VideoFrame->data[1] // U array, linesize = frame width/2
VideoFrame->data[2] // V array, linesize = frame width/2
While YUV420P have theoretically only one plane (according to Wikipedia, YUV420P is a planar format, then Y, U, V data are grouped together).
So, i don't know how to proceed to convert my array where Y, U, V data are separated into RGB24, using swscale.

Please help me, thanks :)
解决方案
av_frame_alloc only allocates memory for the frame object itself, it does not allocate memory to store the image data. Have you done:

FillVect.resize( avpicture_get_size( PIX_FMT_RGB24, FrameWidth, FrameHeight ) );

somewhere in your code before calling avpicture_fill? Or some other way to make sure FillVect allocates enough memory to keep the whole decoded picture?

Did you try to run it under valgrind to see what exactly trigges SEGFAULT?

                        
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