static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,

                               int buf_size)

{

    HEVCParserContext *ctx = s->priv_data;

    ParseContext       *pc = &ctx->pc;

    int i;



    for (i = 0; i < buf_size; i++) {

        int nut;



        pc->state64 = (pc->state64 << 8) | buf[i];



        if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)

            continue;



        nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;

        

        if ((nut >= HEVC_NAL_VPS && nut <= HEVC_NAL_AUD) || nut == HEVC_NAL_SEI_PREFIX ||

            (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {

            if (pc->frame_start_found) {

                pc->frame_start_found = 0;

                return i - 5;

            }

        } else if (nut <= HEVC_NAL_RASL_R ||

                   (nut >= HEVC_NAL_BLA_W_LP && nut <= HEVC_NAL_CRA_NUT)) {

            int first_slice_segment_in_pic_flag = buf[i] >> 7;

            if (first_slice_segment_in_pic_flag) {

                if (!pc->frame_start_found) {

                    pc->frame_start_found = 1;

                } else { 

                    pc->frame_start_found = 0;

                    return i - 5;

                }

            }

        }

    }



    return END_NOT_FOUND;

}
