linux平台下 pag文件 输出的 图片 不流畅

[seu070507]

L
Uploading pag_issue.zip…
inux 平台下，稍微修改了demo的code，pag文件输出的图片，或者合成的视频卡顿不流畅， 怀疑pag解析过程中有丢帧问题，
但也可能是我门使用的方式问题，还请解答一下！

主要函数：
MakeOffscreen
pagPlayer->setProgress
pagPlayer->flush()
pagSurface->readPixels

代码片段：
`int processPagFile(std::shared_ptrpag::PAGFile pagFile, const char* outfile, int imageWidth, int offset, int64_t startTime)
{
if (pagFile == nullptr) {
printf("libpag: processPagFile pagFile is nullptr!!!\n");
return -1;
}

printf("libpag: processPagFile start.\n");

int actualWidth = pagFile->width();

if (imageWidth > 0)
actualWidth = imageWidth;
int actualHeight = actualWidth * pagFile->height() / pagFile->width();
auto pagSurface = pag::PAGSurface::MakeOffscreen(actualWidth, actualHeight);
if (pagSurface == nullptr) {
printf("libpag: processPagFile pagSurface is nullptr!!!\n");
return -1;
}
auto pagPlayer = new pag::PAGPlayer();
pagPlayer->setSurface(pagSurface);
pagPlayer->setComposition(pagFile);

auto totalFrames = TimeToFrame(pagFile->duration(), pagFile->frameRate());
auto currentFrame = 0;

int bytesLength = actualWidth * actualHeight * 4;
int writeIndex = offset;

// check whether dir is exist
std::string outdir = "";
outdir.append(outfile);

if (access(outdir.c_str(), 0) == -1) {
int flag = mkdir(outdir.c_str(), S_IRWXU);
}

auto audioData = pagFile->audioBytes();
AudioWrite(audioData, outdir.c_str());

while (currentFrame <= totalFrames) {
pagPlayer->setProgress(currentFrame * 1.0 / totalFrames);
auto status = pagPlayer->flush();
printf("---currentFrame:%d, flushStatus:%d \n", currentFrame, status);
auto data = new uint8_t[bytesLength];
pagSurface->readPixels(pag::ColorType::BGRA_8888, pag::AlphaType::Premultiplied, data,
actualWidth * 4);

writeIndex++;
std::string imageName = std::to_string(writeIndex);
BmpWrite(data, actualWidth, actualHeight, outdir.c_str(), imageName.c_str());

delete[] data;

currentFrame++;

}

delete pagPlayer;

printf("libpag: processPagFile timeCost:%fs \n", (GetTimer() - startTime) * 1.000f / 1000000);
printf("libpag: processPagFile writeIndex:%d \n", writeIndex);

return writeIndex;
}`

[domchen]

这是个while循环，根本没有实时渲染，不存在丢帧的概念。你注意一下素材的帧率，和浮点误差。应该是计算的progress有偏移导致定位错了帧。用PAGPlayer.nextFrame()会更加准确。