while ((video_st && !video_is_eof) || (audio_st && !audio_is_eof)) {

        /* Вычисление текущего аудио и видео времени */
        audio_time = (audio_st && !audio_is_eof) ? audio_st->pts.val * av_q2d(audio_st->time_base) : INFINITY;
        video_time = (video_st && !video_is_eof) ? video_st->pts.val * av_q2d(video_st->time_base) : INFINITY;



        if (!flush &&
            (!audio_st || audio_time >= STREAM_DURATION) &&
            (!video_st || video_time >= STREAM_DURATION)) {
            flush = 1;
        }

        /* write interleaved audio and video frames */
        if (audio_st && !audio_is_eof && audio_time <= video_time) {
            write_audio_frame(oc, audio_st, flush);
        }
        else if (video_st && !video_is_eof && video_time < audio_time) {

            write_video_frame(oc, video_st, flush);
        }
    }