怎么使用excel输入和表输出控件
时间: 2024-05-25 08:13:47 浏览: 160
Excel输入和表输出控件是常用的数据处理控件,可以方便地将数据从Excel中导入到页面中,或将页面数据导出到Excel表格中。
使用Excel输入控件,需要先在页面上创建该控件 seek to %f seconds: %s\n", video_seek_time, av_err2str(ret));
} else {
printf("seek to %f seconds successfully\n", video_seek_time);
}
// 清空跳转标志
video_seek_time = 0;
}
// 读取一帧数据
ret = av_read_frame(input_context, packet);
if (ret < 0) {
printf("failed to read frame: %s\n", av_err2str(ret));
break;
}
// 处理视频帧
if (packet->stream_index == video_stream->index) {
// 将数据包解码成帧数据
ret = avcodec_send_packet(input_context->streams[video_stream->index]->codec, packet);
if (ret < 0) {
printf("failed to send packet to video decoder: %s\n", av_err2str(ret));
av_packet_unref(packet);
continue;
}
while (ret >= 0) {
ret = avcodec_receive_frame(input_context->streams[video_stream->index]->codec, frame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
break;
} else if (ret < 0) {
printf("failed to receive frame from video decoder: %s\n", av_err2str(ret));
break;
}
// 转换像素格式
AVFrame *converted_frame = av_frame_alloc();
converted_frame->width = video_width;
converted_frame->height = video_height;
converted_frame->format = AV_PIX_FMT_YUV420P;
av_frame_get_buffer(converted_frame, 32);
av_image_copy(converted_frame->data, converted_frame->linesize,
(const uint8_t **)frame->data, frame->linesize,
frame->format, frame->width, frame->height);
// 编码视频帧
ret = avcodec_send_frame(video_codec_context, converted_frame);
if (ret < 0) {
printf("failed to send frame to video encoder: %s\n", av_err2str(ret));
av_frame_free(&converted_frame);
av_packet_unref(packet);
continue;
}
while (ret >= 0) {
ret = avcodec_receive_packet(video_codec_context, packet);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
break;
} else if (ret < 0) {
printf("failed to receive packet from video encoder: %s\n", av_err2str(ret));
break;
}
// 设置时间戳和PTS
packet->stream_index = video_stream->index;
packet->pts = av_rescale_q(packet->pts, input_context->streams[video_stream->index]->time_base, video_stream->time_base);
packet->dts = av_rescale_q(packet->dts, input_context->streams[video_stream->index]->time_base, video_stream->time_base);
packet->duration = av_rescale_q(packet->duration, input_context->streams[video_stream->index]->time_base, video_stream->time_base);
// 发送数据包到推流服务器
ret = av_write_frame(output_context, packet);
if (ret < 0) {
printf("failed to write packet to output context: %s\n", av_err2str(ret));
av_packet_unref(packet);
continue;
}
av_packet_unref(packet);
}
av_frame_free(&converted_frame);
}
}
// 处理音频帧
if (packet->stream_index == audio_stream->index) {
// 将数据包解码成帧数据
ret = avcodec_send_packet(input_context->streams[audio_stream->index]->codec, packet);
if (ret < 0) {
printf("failed to send packet to audio decoder: %s\n", av_err2str(ret));
av_packet_unref(packet);
continue;
}
while (ret >= 0) {
ret = avcodec_receive_frame(input_context->streams[audio_stream->index]->codec, frame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
break;
} else if (ret < 0) {
printf("failed to receive frame from audio decoder: %s\n", av_err2str(ret));
break;
}
// 编码音频帧
ret = avcodec_send_frame(audio_codec_context, frame);
if (ret < 0) {
printf("failed to send frame to audio encoder: %s\n", av_err2str(ret));
av_packet_unref(packet);
continue;
}
while (ret >= 0) {
ret = avcodec_receive_packet(audio_codec_context, packet);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
break;
} else if (ret < 0) {
printf("failed to receive packet from audio encoder: %s\n", av_err2str(ret));
break;
}
// 设置时间戳和PTS
packet->stream_index = audio_stream->index;
packet->pts = av_rescale_q(packet->pts, input_context->streams[audio_stream->index]->time_base, audio_stream->time_base);
packet->dts = av_rescale_q(packet->dts, input_context->streams[audio_stream->index]->time_base, audio_stream->time_base);
packet->duration = av_rescale_q(packet->duration, input_context->streams[audio_stream->index]->time_base, audio_stream->time_base);
// 发送数据包到推流服务器
ret = av_write_frame(output_context, packet);
if (ret < 0) {
printf,然后配置其属性和事件。常见的属性包括控件名称、Excel文件路径、Sheet名称、起始行("failed to write packet to output context: %s\n", av_err2str(ret));
av_packet_unref(packet);
continue;
列、数据范围等;常见的事件包括数据读取完成事件和数据读取失败事件。在数据读取 }
av_packet_unref(packet);
}
}
}
}
// 写入文件尾
av_write_trailer完成事件中,可以通过代码将读取的数据显示在页面上,或者进行其他处理,例如保存到数据库中。
(output_context);
// 释放资源
avcodec_free_context(&video_codec_context);
avcodec_free_context(&audio_codec使用表输出控件,也需要先创建该控件,然后配置其属性和事件。常见的属性包括控_context);
avformat_close_input(&input_context);
if (output_context != NULL && !(output_context->oformat->flags &件名称、输出文件路径、Sheet名称、起始行列、数据范围等;常见的事件包括数据输出完成 AVFMT_NOFILE)) {
avio_close(output_context->pb);
}
avformat_free_context(output_context);
av_packet事件和数据输出失败事件。在数据输出完成事件中,可以通过代码提示用户下载导出的Excel文件,或者进行_free(&packet);
av_frame_free(&frame);
// 修改推流状态
push_status = 0;
return NULL;
其他处理,例如将文件保存到服务器中。
需要注意的是,Excel输入和表输出控件需要在服务器上安装}
int main(int argc, char **argv)
{
int ret = 0;
// 初始化FFmpeg库
ret = init相应的组件才能正常使用,例如Microsoft Office Excel组件。此外,在使用控件时也需要注意数据_ffmpeg();
if (ret < 0) {
printf("failed to initialize FFmpeg: %s\n", av_err2str格式和数据异常处理等问题,以保证数据的正确性和安全性。
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