视频压缩的流程

来源：互联网发布：网络信息化建设需求编辑：程序博客网时间：2024/06/09 03:42

初始化：
av_register_all

avformat_alloc_output_context2

avcodec_find_encoder

avcodec_alloc_context3

av_dict_set

//打开编码器
avcodec_open2

//Add a new stream to output,should be called by the user before avformat_write_header() for muxing
avformat_new_stream

//Open output URL,set before avformat_write_header() for muxing
avio_open

//Write File Header
avformat_write_header(ofmt_ctx, NULL);

循环编码：编码时需写入PTS, enc_pkt.dts = enc_pkt.pts;
avcodec_alloc_frame

//Frame分配内存
avpicture_fill

av_init_packet

//编码
avcodec_encode_video2
av_frame_free

//设置DTS -->PTS ,通过DTS\PTS实现音视频同步
enc_pkt.pts = av_rescale_q(framecnt*calc_duration, time_base_q, time_base);
//DTS -->PTS
enc_pkt.dts = enc_pkt.pts;

av_interleaved_write_frame
av_free_packet

flush:
while (1) {
av_init_packet

avcodec_encode_video2

//Write PTS

}

close:
释放内存。。。

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