關於ffmpeg的avpacket裡的pts問題

                    在進行儲存視頻流的時候，必須將avpacket裡的pts設定好，否則會出現視頻過快或過慢的情況，在此主要用到ffmpeg裡的av_rescale_rnd函數，可看之前的部落格。

               

                      //time_base:time_base.num/time_base.den,1/9000

                      AVRational time_base1=in_stream->time_base;

//Duration between 2 frames (us)
int64_t calc_duration=(double)AV_TIME_BASE/av_q2d(in_stream->r_frame_rate);
//Parameters
packet->pts=(double)(frame_index*calc_duration)/(double)(av_q2d(time_base1)*AV_TIME_BASE);
packet->dts=packet->pts;
packet->duration=(double)calc_duration/(double)(av_q2d(time_base1)*AV_TIME_BASE);
frame_index++;
        }
/* copy packet */
//轉換PTS/DTS（Convert PTS/DTS） packet->pts*out_stream->time_base.den/  in_stream->time_base.den算出現在的時間
packet->pts = av_rescale_rnd(packet->pts, out_stream->time_base.den,in_stream->time_base.den,AV_ROUND_NEAR_INF);
packet->dts = av_rescale_rnd(packet->dts, out_stream->time_base.den,in_stream->time_base.den,AV_ROUND_NEAR_INF);
packet->duration = av_rescale_q(packet->duration, in_stream->time_base,out_stream->time_base);
packet->pos = -1;
packet->stream_index=0;