我使用FFmpeg6.0+QT去把QImage合成视频.但是我不管怎么循环去保存,都只有一个一帧的视频
qDebug()<<"================================================================start======================================================================";
int ret;
QImage image("/sdcard/photo/20210101130446468.jpg");
int imagewidth = image.width();
int imageheight = image.height();
// 初始化 FFmpeg
qDebug()<<"avdevice_register_all()";
avdevice_register_all(); //初始化所有设备
qDebug()<<"formatContext = avformat_alloc_context()";
formatContext = avformat_alloc_context();//分配format上下文
qint64 timeT = QDateTime::currentMSecsSinceEpoch();//毫秒级时间戳
QString outputFileName = QString("/sdcard/").append("ffmpeg").append(QString::number(timeT)).append(".mp4");
//第三个参数可以直接使用nullptr 根据outputFileName的后缀自动识别
qDebug()<<"avformat_alloc_output_context2(&formatContext, nullptr, \"mp4\", outputFileName.toUtf8().constData())";
ret = avformat_alloc_output_context2(&formatContext, nullptr, nullptr, outputFileName.toUtf8().constData());
qDebug()<<"ret===="<<ret;
qDebug()<<"formatContext===="<<formatContext;
qDebug()<<"formatContext->oformat = av_guess_format(nullptr, outputFileName.toUtf8().constData(), nullptr);";
formatContext->oformat = av_guess_format(nullptr, outputFileName.toUtf8().constData(), nullptr);
qDebug() << "avio_open(&formatContext->pb, outputFileName.toUtf8().constData(), AVIO_FLAG_WRITE) < 0";
// 打开输出文件
if (avio_open(&formatContext->pb, outputFileName.toUtf8().constData(), AVIO_FLAG_WRITE) < 0) {
qDebug() << "Failed to open output file";
return;
}
qDebug() << "AVStream* stream = avformat_new_stream(formatContext, nullptr);";
// 创建一个AVStream对象
AVStream* stream = avformat_new_stream(formatContext, nullptr);
if (!stream) {
qDebug() << "Failed to create output stream";
return;
}
qDebug() << "AVCodecParameters* codecParameters = stream->codecpar;";
// 配置AVCodecContext
AVCodecParameters* codecParameters = stream->codecpar;
codecParameters->codec_type = AVMEDIA_TYPE_VIDEO;
codecParameters->codec_id = AV_CODEC_ID_H264; // 使用H.264编码器
codecParameters->width = imagewidth;
codecParameters->height = imageheight;
qDebug() << " const AVCodec* codec = avcodec_find_encoder(codecParameters->codec_id);";
qDebug() << "const AVCodec* codec = avcodec_find_encoder(codecParameters->codec_id);";
// 打开编解码器
const AVCodec* codec = avcodec_find_encoder(codecParameters->codec_id);
AVCodecContext* codecContext = avcodec_alloc_context3(codec);
codecContext->width = imagewidth;
codecContext->height = imageheight;
codecContext->pix_fmt = AV_PIX_FMT_YUV420P;
codecContext->time_base = {1, 30}; // 设置编码器的时间基为 1秒/30帧
codecContext->framerate = {30, 1}; // 设置编码器的帧率为 30fps
qDebug() << "AV_PIX_FMT_YUV420P====="<<AV_PIX_FMT_YUV420P;
qDebug() << "codecContext->pix_fmt====="<<codecContext->pix_fmt;
qDebug() << "avcodec_open2(codecContext, codec, nullptr);";
//设置完成编码格式以后要立刻打开,要不然调用avcodec_parameters_to_context的时候会重置编码
ret = avcodec_open2(codecContext, codec, nullptr);
if(ret < 0){
qDebug() << "Failed to avcodec_open2";
return;
}
qDebug() << "avcodec_parameters_to_context(codecContext, codecParameters);";
// 将编码器参数复制到输出流
avcodec_parameters_to_context(codecContext, codecParameters);
// 检查编解码器支持的像素格式
const AVPixelFormat* pixFmt = codec->pix_fmts;
qDebug() << "while";
while (*pixFmt != AV_PIX_FMT_NONE) {
qDebug() << av_get_pix_fmt_name(*pixFmt);
++pixFmt;
}
qDebug() << " avformat_write_header(formatContext, nullptr);";
// 写入头部信息
avformat_write_header(formatContext, nullptr);
int num = 0;
while (num < 1200) {
qDebug() << " AVFrame* frame = av_frame_alloc();";
// 逐个写入图像帧
AVFrame* frame = av_frame_alloc();
if (!frame) {
qDebug() << "Failed to allocate frame.";
return;
}
qDebug() << "frame->format = AV_PIX_FMT_YUV420P";
frame->format = AV_PIX_FMT_YUV420P;
frame->width = imagewidth;
frame->height = imageheight;
frame->pts = av_rescale_q(stream->nb_frames, stream->time_base, codecContext->time_base);
if (av_frame_get_buffer(frame, 0) < 0) {
qDebug() << "Failed to allocate frame buffer.";
av_frame_free(&frame);
return;
}
// 图像格式转换
SwsContext* swsContext = sws_getContext(imagewidth, imageheight, AV_PIX_FMT_BGR32,
frame->width, frame->height, AV_PIX_FMT_YUV420P,
SWS_BICUBIC, nullptr, nullptr, nullptr);
if (!swsContext) {
qDebug() << "Failed to create SwsContext.";
av_frame_free(&frame);
return;
}
uint8_t* destData[4] = {frame->data[0], frame->data[1], frame->data[2], nullptr};
int destLinesize[4] = {frame->linesize[0], frame->linesize[1], frame->linesize[2], 0};
image = image.convertToFormat(QImage::Format_RGB32);
const uchar* bits = image.constBits();
int bytesPerLine = image.bytesPerLine();
// 函数返回的值是转换后的图像的输出行数。输出的图像高度为图像像素。
ret = sws_scale(swsContext, &bits, &bytesPerLine, 0, image.height(), destData, destLinesize);
qDebug() << "sws_scale ret==="<<ret;
//函数用于释放由 sws_getContext 函数创建的图像格式转换上下文
sws_freeContext(swsContext);
qDebug() << "AVPacket packet;";
// 编码并写入视频帧
AVPacket packet;
av_init_packet(&packet);
packet.data = nullptr;
packet.size = 0;
int code = -1;
// 接收输出包
while (code < 0) {
ret = avcodec_send_frame(codecContext, frame);
qDebug() << "avcodec_send_frame ret===="<<ret;
code = avcodec_receive_packet(codecContext, &packet);
qDebug() << "while avcodec_receive_packet====" << code;
if(code == 0){
// 处理输出包
ret = av_interleaved_write_frame(formatContext, &packet);
qDebug() << "av_interleaved_write_frame==================" << ret;
av_packet_unref(&packet);
}
}
qDebug() << "av_frame_free(&frame);";
av_frame_free(&frame);
qDebug()<<"num==============================================="<<num;
++num;
}
//写入尾部信息
ret = av_write_trailer(formatContext);
qDebug() << "av_write_trailer(formatContext) ret==="<<ret;
//av_frame_free(&frame);
qDebug()<<"=============================================================stop=========================================================================";
这是我的视频:love.sunchip-ad.com/qt/ffmpeg1609507548763.mp4
