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ffmpeg sws_scale crash when convert video frame NV12 buffer to I420 buffer
5 février 2017, par AnhTuan.NgI have a stream of 2048x896 (NV12 format) video frames, and i have to crop its to 1936x872 I420 frames, then encoding to new 1936x872MP4 file.
Crop frame from 2048x986 to 1936x872 image
I use openCV to crop the original NV12 frames and use FFMPEG sws_scale to convert NV12 to I420 format. But My app crash on sws_scale function.
I also tried with some another crop size, and see that with 1920x872 crop frame size, it work !
This is my code :// FFmpeg library
extern "C" {
#include <libavformat></libavformat>avformat.h>
#include <libavcodec></libavcodec>avcodec.h>
#include <libswscale></libswscale>swscale.h>
}
//Using openCV library:
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#ifdef _DEBUG
#pragma comment(lib, "opencv_core2411d.lib")
#pragma comment(lib, "opencv_highgui2411d.lib")
#pragma comment(lib, "opencv_imgproc2411d.lib")
#else
#pragma comment(lib, "opencv_core2411.lib")
#pragma comment(lib, "opencv_highgui2411.lib")
#pragma comment(lib, "opencv_imgproc2411.lib")
#endif
using namespace cv;
void RotateOpenCVMatrix(Mat& src, double angle, Mat& dst)
{
Mat tempMat;
transpose(src, tempMat);
flip(tempMat, dst, 1); //transpose+flip(1)=CW
}
void CropNV12ImageFrame(unsigned char *srcBuff, unsigned char *resultBuff,
int srcWidth, int srcHeight, int x, int y, int cropWidth, int cropHeight,
BOOL isRotate)
{
//create src_NV12 matrix:
Mat src_Y_img;
Mat src_UV_img;
Mat crop_Y_mat;
Mat crop_UV_mat;
src_Y_img.create(srcHeight, srcWidth, CV_8UC1);
src_UV_img.create(srcHeight / 2, srcWidth, CV_8UC1);
memcpy(src_Y_img.data, srcBuff, srcWidth * srcHeight);
memcpy(src_UV_img.data, srcBuff + srcWidth * srcHeight, srcWidth * srcHeight / 2);
//Create result Y plane matrix:
crop_Y_mat = src_Y_img(cv::Rect(x, y, cropWidth, cropHeight)).clone();
crop_UV_mat = src_UV_img(cv::Rect(x, y / 2, cropWidth, cropHeight / 2)).clone();
//Rotate by openCV:
if (isRotate)
{
Mat result_Y_mat;
Mat result_UV_mat;
RotateOpenCVMatrix(crop_Y_mat, 90, result_Y_mat);
RotateOpenCVMatrix(crop_UV_mat, 90, result_UV_mat);
//Mem copy to output data buffer:
memcpy(resultBuff, result_Y_mat.data, cropWidth * cropHeight);
memcpy(resultBuff + cropWidth * cropHeight, result_UV_mat.data, cropWidth * cropHeight / 2);
}
else
{
memcpy(resultBuff, crop_Y_mat.data, cropWidth * cropHeight);
memcpy(resultBuff + cropWidth * cropHeight, crop_UV_mat.data, cropWidth * cropHeight / 2);
}
}
int ConvertColor(unsigned char *srcbuff, unsigned char *targetBuff, unsigned int width, unsigned int height, AVPixelFormat srcFormat, AVPixelFormat targetFormat)
{
int ret = 0;
//create the conversion context
struct SwsContext *swsContext = sws_getContext(
width, height, srcFormat, // source
width, height, targetFormat, // target
SWS_BILINEAR,
NULL, NULL, NULL
);
if (swsContext < 0) {
return -1;
}
// allocate frame
AVFrame *pSrcFrame = av_frame_alloc();
AVFrame *pTargetFrame = av_frame_alloc();
// source frame
avpicture_fill(
(AVPicture*)pSrcFrame,
(const uint8_t *)srcbuff,
srcFormat,
width,
height
);
// target frame
if (srcFormat != AV_PIX_FMT_RGBA)
avpicture_fill(
(AVPicture*)pTargetFrame,
(const uint8_t *)targetBuff,
targetFormat,
width,
height
);
else
avpicture_fill(
(AVPicture*)pTargetFrame,
(const uint8_t *)targetBuff,
targetFormat,
1936,
872
);
ret = sws_scale(
swsContext, // sws context
// source
pSrcFrame->data, // source
pSrcFrame->linesize, // source stride
0, // slice Y
height, // slice H
// target
pTargetFrame->data, // target
pTargetFrame->linesize // target stride
);
av_frame_free(&pSrcFrame);
av_frame_free(&pTargetFrame);
sws_freeContext(swsContext);
return ret;
}
void CropVideoFrame(BYTE* nv12BufferInput, BYTE* i420BufferOutput, int inWidth, int inHeight, int outWidth, int outHeight)
{
BYTE *cropNV12Image = new BYTE[outWidth* outHeight * 3 / 2 + 1];
//Get 4 horizontal camera img buffer:
CropImageFrame(input, cropNV12Image[0], inWidth, inHeight, 0, 0, outWidth, outHeight, FALSE);
//Convert from NV21 to I420p:
ConvertColor(cropNV12Image[0], i420BufferOutput, outWidth, outHeight, AV_PIX_FMT_NV12, AV_PIX_FMT_YUV420P);
//Free memory:
delete[] cropNV12Image;
} -
FFMPEG Encoder error when playback with 1936 width video size
5 février 2017, par AnhTuan.NgI have a 4096x1760 YUV-NV12 video frames stream and i have to split it to 4 frames have resolution 1936x872, then encode them to 4 video file (Like bellow picture)
Crop frame
My algorithm is :
1. Using openCV to crop and splitting (4096x1760) NV12 frame to 4 (1936x872) down size.
2. Using FFMPEG swscale() to convert RGBA to I420 buffer
3. Using FFMpeg to encode 4 (1936x872) frames to 4 video files.But i have a trouble, that 4 video encoded have error signals, Just horizontal stripes on screen (such as zebra skin, So sad !)
Video error
I think error caused by encoder, because when i change crop size to 1920x872, All thing seem be ok (By one step, I dump buffer data to bmp image to check, and every thing look good !)And, what a surprise ! When I change my crop famre size from 1936x872 to 1920x872. All things work done, Video output can be playing so smooth !
So I think this error because my FFMPEG encoder setting up wrong. Please tell me why and show me a way to fix it ! Thanks you !
this is my code :
-My define :
#define SIDE_FRAME_WIDTH 4096
#define SIDE_FRAME_HEIGHT 1760
#define SINGLE_SIDE_WIDTH 1936 //1920 is woking!
#define SINGLE_SIDE_HEIGHT 872 //872
#define SIDE_CROP_WIDTH 1936
#define SIDE_CROP_HEIGHT 872My Splitting thread :
void splittingThread(SplitingThreadParam &param)
{
Converter *pConverter = (Converter*)param.parentParamClass;
BYTE* cropRGBABuff[4];
for (int i = 0; i < 4; i++)
cropRGBABuff[i] = new BYTE[SINGLE_SIDE_WIDTH*SINGLE_SIDE_HEIGHT * 4];
//Split:
pConverter->OpenCVSplittingSideFrame(param.inputBuff, SIDE_FRAME_WIDTH, SIDE_FRAME_HEIGHT, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, cropRGBABuff[0], cropRGBABuff[1], cropRGBABuff[2], cropRGBABuff[3]);
//Convert to I420:
pConverter->ConvertColor(cropRGBABuff[0], param.out1Buff, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV420P);
pConverter->ConvertColor(cropRGBABuff[1], param.out2Buff, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV420P);
pConverter->ConvertColor(cropRGBABuff[2], param.out3Buff, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV420P);
pConverter->ConvertColor(cropRGBABuff[3], param.out4Buff, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV420P);
//pConverter->DumpBufferData(param.out1Buff, SINGLE_SIDE_WIDTH, SINGLE_SIDE_HEIGHT, 1);
}My Splitting function :
void Converter::OpenCVSplittingSideFrame(BYTE *input, unsigned int srcWidth, unsigned int srcHeight,
unsigned int cropWidth, unsigned int cropHeight,
BYTE *out1, BYTE *out2, BYTE *out3, BYTE *out4)
{
Mat nv12Mat;
Mat rgbMat;
Mat rgbCropImg[4];
//Create YUV Matrix:
nv12Mat.create(srcHeight * 3 / 2, srcWidth, CV_8UC1);
memcpy(nv12Mat.data, input, srcWidth * srcHeight * 3 / 2);
//Create RGB matrix:
rgbMat.create(srcHeight, srcWidth, CV_8UC4);
//Convert YUV to RGB:
cvtColor(nv12Mat, rgbMat, COLOR_YUV2RGBA_NV21);
//Crop:
CropMatrix(rgbMat, rgbCropImg[0], 0, 0, cropWidth, cropHeight);
CropMatrix(rgbMat, rgbCropImg[1], 0, SIDE_CROP_HEIGHT, cropWidth, cropHeight);
CropMatrix(rgbMat, rgbCropImg[2], SIDE_CROP_WIDTH, 0, cropWidth, cropHeight);
CropMatrix(rgbMat, rgbCropImg[3], SIDE_CROP_WIDTH, SIDE_CROP_HEIGHT, cropWidth, cropHeight);
//Copy from matrix to output buffer:
memcpy(out1, rgbCropImg[0].data, cropWidth * cropHeight * 4);
memcpy(out2, rgbCropImg[1].data, cropWidth * cropHeight * 4);
memcpy(out3, rgbCropImg[2].data, cropWidth * cropHeight * 4);
memcpy(out4, rgbCropImg[3].data, cropWidth * cropHeight * 4);
}Convert color range to RGBA to I420 function :
int Converter::ConvertColor(unsigned char *srcbuff, unsigned char *targetBuff, unsigned int width, unsigned int height, AVPixelFormat srcFormat, AVPixelFormat targetFormat)
{
int ret = 0;
//create the conversion context
struct SwsContext *swsContext = sws_getContext(
width, height, srcFormat, // AV_PIX_FMT_NV12, // source
width, height, targetFormat, // AV_PIX_FMT_YUV420P, // target: GL_RGBA
SWS_BILINEAR,
NULL, NULL, NULL
);
if (swsContext < 0) {
return -1;
}
// allocate frame
AVFrame *pSrcFrame = av_frame_alloc();
AVFrame *pTargetFrame = av_frame_alloc();
// source frame
avpicture_fill(
(AVPicture*)pSrcFrame,
(const uint8_t *)srcbuff,
srcFormat,
width,
height
);
// target frame
if (srcFormat != AV_PIX_FMT_RGBA)
avpicture_fill(
(AVPicture*)pTargetFrame,
(const uint8_t *)targetBuff,
targetFormat,
width,
height
);
else
avpicture_fill(
(AVPicture*)pTargetFrame,
(const uint8_t *)targetBuff,
targetFormat,
1936,
872
);
ret = sws_scale(
swsContext, // sws context
// source
pSrcFrame->data, // source
pSrcFrame->linesize, // source stride
0, // slice Y
height, // slice H
// target
pTargetFrame->data, // target
pTargetFrame->linesize // target stride
);
av_frame_free(&pSrcFrame);
av_frame_free(&pTargetFrame);
sws_freeContext(swsContext);
return ret;
}My encoder setting :
EncoderContext encoderCtx;
encoderCtx.vCodecId = VIDEO_CODEC_H264;
encoderCtx.aCodecId = AUDIO_CODEC_NONE;
encoderCtx.numAudioChannel = 0;
encoderCtx.eFormat = BEYOND_ENCODER_MP4;
encoderCtx.videoBitrate = 10000000;
encoderCtx.audioBitrate = 0;
encoderCtx.audioBitrate = 0;
encoderCtx.timeBaseDen = config->time_base_den;
encoderCtx.timeBaseNum = config->time_base_num;
encoderCtx.width = SINGLE_SIDE_WIDTH;
encoderCtx.height = SINGLE_SIDE_HEIGHT;
CString filePath(config->savePath.c_str());
CString filePath2;
filePath2.Format(_T("%s_%d.mp4"), filePath, i);
CT2A multibyte(filePath2, CP_UTF8);
encoderCtx.outFileName = multibyte;Thanks all for your help !
-
Using ffmpeg showwaves as circle. Is it possible ?
14 décembre 2020, par Tudor-Radu BarbuShowwaves are normally used in a horizontal manner.
Is it possible to display the waveform in a circle ?


Something like this ?




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